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PRACTICAL IRON FOUNDING 



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Whittaker AND Co., 2, White Hart Street, London, E.C. 



PRACTICAL 
IRON FOUNDING 



BY 



JOSEPH G. HORNER, A.M.I.Mech.E. 

AUTHOK OK "PKINCIl'LES OF PATTERN MAKING," " METAL TURNING," 
"PRINCIPLES OP FITTING," ETC. 



With Two Hundred and Eighty -Three Illustrations 



FOURTH EDITION, THOROUGHLY REVISED 
AND ENLARGED 



NEW YOEK 

D. VAN NOSTEAND COMPANY 

25, PARK PLACE 
LONDON: WHITTAKER AND CO. 

1914 




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• » * 

• • • 







CHISWIClv PRESS : CHARLES WHITTINGHAM AND CO. 
TOOKS COURT, CHANCERY LANE, LONDON. 



1 



PREFACE TO FIRST EDITION 

This is an attempt to give a condensed account of 
the principles and practice of Iron Founding. It is 
written both for the student and for the practical 
man. I have stated and explained principles, and 
have also included the most recent practice, particu- 
larly as it relates to the two branches of machine 
moulding and the melting of iron. 

Joseph Horner. 



PREFACE TO FOURTH EDITION 

Since this voluine was written o-reat chan^'es have 
been accomplished in the Iron Foundry. This is 
the explanation of the fact that the amount of 
matter in the present edition is just double that of 
the previous one, and that certain portions, notably 
that of machine moulding, have been wholly re- 
written . 

Additional examples of moulds have been intro- 
duced, and some new chapters prepared. It is now 
more than an elementary treatise, and should pos- 
sess a correspondingly higher value than the pre- 
vious editions. 

Bath, 1914 



VI 



CONTENTS 

CHAPTER PAGE 

I. Principles ....... 1 

II. Sands and their Preparation ... 4 

III. Iron — Melting and Testing ... 28 

IV. Cupolas, Blast, and Ladles ... 47 
V. The Shops, and their Equipment . . 71 

VI. Moulding Boxes and Tools . . .93 

VII. Shrinkage — Curving — Fractures — Faults . 113 

VIII. Principles of Green Sand Moulding . . 137 

IX. Examples of Green Sand Moulding . . 163 

X. Dry Sand Moulding ..... 185 

XL Cores 215 

XII. Loam Work 234 

XIII. The Elements of Machine Moulding . . 263 

XIV. Examples of Moulding Machines . . 279 
XV. Machine Moulded Gears .... 329 

XVI. Miscellaneous Economies — Weights of 

Castings 347 

Appendix : 

Tables L Sand Mixtures 385 

II, in. Particulars, " Rapid " Cupolas . . 389 

IV. Particulars, Boot's Blowers . . 392 

V. Sturtevant Fans 393 

VI. Crane Chains 394 

VII. Bopes, various 394 

VIIL Composition of Pig Iron . . . 395 

IX. Mensuration 396 

vii 



Vlll 



CONTENTS 



Appendix — continued 
Tables X. Weights of Various Metals . 

XI. Weights of Cast Iron Cylinders 
XII. Comparative Weights 

XIII. Weights, Cast Iron Balls 

XIV. Decimal Equivalents . 
XV. Decimal Approximations 

Index 



PAGE 

399 
400 
402 
403 
404 
404 
405 



PRACTICAL IRON FOUNDING 

^ CHAPTEK I 

PRINCIPLES 

In this text-book the endeavour will be to explain and 
illustrate in a clear and concise manner the principles 
and practice of iron moulding and founding. Though a 
dirty trade, more of technical skill and forethought are 
required, more difficulties have to be encountered than in 
many trades of more apparent importance. And as it 
is one the practice of which is very varied and extensive, 
and as a thoroughly exhaustive treatment would occupy 
a much larger treatise than this, judicious condensation 
will be necessary. But if we endeavour to go down at 
once to first principles, and gain clear ideas as to the 
fundamentals involved in iron-moulding, we shall be able 
to obtain such a broad grasp of the subject as will assist 
subsequently in the comprehension of details. 

The matrices into which iron is poured in order to 
obtain castings of definite outlines are invariably either 
of sand or iron. The process in which the latter is used 
is a small and comparatively restricted section, known 
as chilling', the former embraces all the ordinary iron 
castings — those the surfaces of which are not required of 
a hard and steely character. Recently, however, the prac- 
tice has been developing of casting pipes, wheels, sash 
weights, etc., in permanent moulds of iron. 

Sand is eminently adapted for casting metals into. 
No material can take its place, because there is none 



2 PBAGTIGAL IRON FOUNDING 

which is at the same time plastic, porous and firm, 
adhesive and refractory. Plasticity is necessary in order 
that the matrix may be moulded into any form, intricate 
or otherwise. Porosity is essential to permit of the escape 
from the moulds of the air and of the gases generated by 
the act of casting, and firmness and adhesiveness are re- 
quired to withstand the liquid pressure of the molten 
metal. A matrix must also be refractory, that is, able to 
resist the disintegrating influence of great heat, and the 
chemical action of the hot iron itself. It must, moreover, 
be cheap, readily available, and not difficult to manipu- 
late. All these qualities are possessed by certain sands, 
and mixtures of sands, and by no other materials. 

The leading branches of moulding derive their names 
from the different kinds of sand mixtures used, termed 
respectively green sand, dry sand, loam, to be explained 
directly. It will suffice just now to remark that the fact 
that sands differ widely in their physical qualities is 
apparent to any observant person, so that while one kind 
will be loose, open, friable, and free, another will appear 
as though clayey, greasy, close, and dense. Advantage 
is taken of these differences in quality to obtain mixtures 
suitable for every class of moulded work, from the thin- 
nest, lightest rain-water pipes to the most massive and 
heaviest engine cylinders and bedplates. Almost in- 
variably, therefore, foundry sand consists of mixtures 
of various separate kinds. By judicious mixture, grades 
of any required character can be obtained. 

To enable the sand to take the requisite definite im- 
pressions and outlines, it is necessary to emiAoy 2)atterns, 
the shapes of which are in the main the counterparts of 
those of the castings wanted. These patterns are in some 
cases absolutely like their castings, but in others they 



PRINCIPLES 3 

resemble them only to a certain extent. Thus, if work is 
to be hollow, the hollow portions, instead of being pro- 
vided in the patterns, may be often much better formed 
in cores: — prints on the patterns indicating their posi- 
tions, and the print impressions affording them support. 
But in much large work, again, the patterns are mere 
skeletons, profile forms, and the mould is prepared 
mainly by a process of " sweeping " or " strickling " up. 

In order to effect delivery of patterns, a process of 
loosening by rapping has to be resorted to, and this, 
together with the lifting or withdrawal, tends to damage 
the mould. To prevent or to minimize this injury, taper 
is given to patterns, that is, their dimensions are slightly 
diminished in their lower portions, or in those which are 
last withdrawn from the mould. 

As iron shrinks during the process of cooling, an allow- 
ance has to be given for this "contraction," by making 
the pattern and mould larger by a corresponding amount 
than the casting is required to be. Moreover, the forms 
of some castings are such that they i'lirce in cooling, and 
for this also provision has properly to be made in their 
patterns. 

Iron when molten behaves similarly to a liquid in all 
respects; hence the conditions of liquid pressure exist in 
all moulds. The iron, therefore, has to be confined at 
the time of pouring by the resistance of large bodies of 
sand enclosed in boxes or flasks, which are weighted, or 
otherwise secured. Sufficient area of entry for the metal 
has to be provided by means of suitable gates and run- 
ners. The shrinkage of metal in mass must receive 
adequate compensation by feeder heads. Owing to the 
irregular outlines of cast work, flasks must be jointed, and 
joints of various kinds have to be made in the mould itself. 



CHAPTEE II 

SANDS, AND THEIR PREPARATION 

Although as stated, sand is not the only material used 
for moulds, yet ninety-nine one-hundredths of the moulds 
made are prepared in sand in some way or another, and 
cast into either moist or dried. Consisting, as this material 
does, of a vast number of distinct particles, it can readily 
be compelled by ramming or pressure to take any re- 
quired outlines and the finest impressions of the pattern. 
Though friable and destitute of cohesion in its natural dry 
condition, it is plastic and coherent when moistened with 
water; so that w^hen in this state it is capable not only 
of receiving but of retaining the impressions made by the 
pattern after its withdrawal. Further, the porosity of the 
sand much assists the free escape of the gases generated 
by casting, and which, in the absence of a free vent, 
would honeycomb the castings with innumerable blow- 
holes. 

But it is obvious that sands are not all alike, and a 
very superficial knowledge of moulding is sufQcient to 
show that different classes of moulds must require differ- 
ent kinds of mixtures of sands. In their judicious choice 
and proper mixture lies very much of the moulder's art; 
so that a foreman moulder will spend several months, or 
even years, in studying and experimenting in various 
mixtures before he gets the very best possible results in 
his shop. 

4 



SANDS, AND THEIB PREPARATION 5 

Choice of sands. — Primarily the choice depends very 
much upon locaHties. When building a new foundry one 
would not go to the opposite end of England to get sand 
to lay down his floor, which will properly be from 2 ft. to 
3 ft. or 4 ft. in depth. He would purchase cheap sand in his 
immediate neighbourhood, and there are few localities in 
which the new red sandstone, the green sand, and chalk 
formations, or the coal measures, do not furnish suitable 
material for the moulder. But there are several localities 
which are famous for some special qualities possessed by 
their sands which render them more suitable for some 
classes of work than for others, and small quantities of 
these sands are often purchased at considerable expense, 
due chiefly to the cost of transit, for special work. Thus, 
though the yellow and greenish-yellow sands usually 
form the basis of the foundry floor, the fine red sands 
are chiefly employed for facing and for fine moulding. 

The names and qualities of some of the best-known 
sands used in this country are summarized below: 

Erith sand, or London sand, is largely used for green, 
and loam moulds. It is suitable for light work, for 
ordinary and moderately heavy castings, and, mixed with 
old loam and cow hair, for loam work. Devizes and Seend 
sands, used in the West of England, are of a yellow or 
greenish-yellow colour, and are used for general and 
heavy work. They are not suitable for the finest work, 
being coarse and close. Worcester is a fine red sand, used 
for fine moulds and for facing moulds, in which a coarser 
sand is used for filling. Falkirk sand is coarse and open, 
and is suitable, therefore, for casting hollow ware into, 
its porosity allowing free vent for the gases. Belfast sand 
is fine ; it is used for general work, is mixed with rock 
sand, and aftbrds excellent facing. Doncaster sand is 



6 PRACTICAL IRON FOUNDING 

suitable for jobbing work. It is of a red colour, and 
moderately open. Winmoor sand is very open, and used 
for strong moulds. Kippax, a yellow sand, is employed 
for cores, and for dry-sand moulds. Mansfield sand is 
close, and suitable for fine work. Derbyshire, Snaitb, 
Shropshire, Cheshire, the Birmingham district, and many 
others, produce good sands of various qualities. Sea sand 
is sometimes used for cores, and rock sand — i.e., rotten 
rock — is employed for imparting strength to weaker 
sands. 

Moulding sands are obtained in the coal measures, the 
new red sandstone, and the green sand and chalk. As 
local foundries largely use local supplies, a knowledge of 
the precise mixing of sands for any one locality has to 
be acquired there, and the experience thus gained is 
modified to be of service when the sands of another 
locality are employed. Nevertheless, there are certain 
general principles to be observed in the mixing and use 
of sands, which apply to all alike. 

The terms f/reen, dry, loam, floor, black, strong, iccak, 
core, facing, burnt, parting, road sands, have exclusive 
reference to mixtures, and physical conditions; none 
whatever to geological character, or to locality. 

Sand is green when the mixture is used in its natural 
condition, that is, damp, or mixed with just sufficient 
water to render it coherent. Immediately after the pattern 
has been withdrawn therefrom, the mould is ready, ex- 
cept for the necessary cleaning and mending up, and 
blackening, to receive the metal. It is also termed n-eak 
sand to distinguish it from the other mixtures, which by 
comparison therewith are strong, i.e., possessed of superior 
binding qualities — having more body — more coherence. 

Floor sand, — Every time that a casting is poured, the 



SANDS, AND THEIU PREPARATION 7 

sand in the mould becomes baked dry by the heat of the 
metal, and before being allowed to mingle with the floor 
sand it is passed through a riddle to free it from small 
particles of metal, lifters, nails, etc., and is then moistened 
with water from a bucket or can, or hose pipe, and dug 
over two or three times, and it is then ready for use once 
more. The floor sand or black sand, therefore, forms an 
accumulation, always damp, always ready for filling 
boxes, or for moulding patterns by a process of bedding- 
in. It possesses no strength, and is only used for box- 
filling. 

When a mould requiring a fine sand is large, or only 
of moderate size, then the common sand would be used 
for its main body — or for box-filling — and only those 
portions which come next the pattern, and for an inch 
or so away from it, would be made with the more ex- 
pensive sand. There are certain primary methods of 
preparing sands which are, however, followed in all shops, 
no matter what kinds or what proportions are used. 
Except for mere box- filling, no sand is ever used just in 
the condition in which it is dug out of the quarry or pit. 
It is mixed wdth other sands, or other ingredients, and 
with water. Omitting loam mixtures we may therefore 
divide all prepared moulding sands into two classes, those 
which are used for box-filling^ and those employed for 
facing. 

In reference to the first, little preparation is required. 
The floor of a foundry is composed entirely of sand, 
which is being used and cast into over and over again, 
year after year, and only such portions as become burnt 
by direct contact with the castings are ever removed and 
thrown away. This sand is receiving continual addi- 
tions of new facing sand, used once in contact with the 



8 PB. ACTIO AL IB ON FOUNDING 

castings, and then, excepting the burnt portions, allowed 
to mingle with the floor sand. 

Facing sand. — The actual sand which is rammed 
around, and in immediate contact with, the pattern, is 
termed facing sand, because it forms the actual faces of 
the mould, against which the metal is poured. This is the 
true moulding material, on the composition and character 
of which the quality of the casting itself depends in a 
very large measure, and which is varied by the skill and 
•experience of the founder to suit different classes of 
work. Facing sands are made to vary in strength, 
porosity, and binding qualities, for different kinds of 
work, the reasons of which will be apparent as we dis- 
cuss the different kinds of moulds. Some of these are 
more porous and sharp than others, and being 02)en, are 
suitable for light, thin castings, being more or less self- 
venting. Some of the more open sands are used alone, 
but most kinds require tempering by admixture with 
those of opposite qualities, in order to fit them for their 
specific uses. Thus strong sands, or those having a good 
body, or closeness of texture, are mixed in variable pro- 
portions with the open sharp sands, and by varying their 
proportions, sand, like iron, can be obtained in any re- 
quired grade. 

Hence the facing sands are prepared by a careful pro- 
cess of due proportioning of ingredients adapted to the 
several classes of work for which they are specially re- 
quired. 

For light, and for heavy work, and for all intermediate 
classes, the kinds and proportions of sands used, and 
the quantity of coal dust intermixed, will vary, and even 
in different parts of the same mould. In parts subject to 
much pressure, the sand should be close, rammed hard. 



SANDS, AND THEIB PBEPABATION 9 

and well vented; and in sections where the opposite 
conditions exist, the sand may be light and open. It is 
therefore impossible to give any precise rules. But the 
broad principles upon which such mixtures are propor- 
tioned can be indicated. 

For lieavy moulds — that is, moulds for massive cast- 
ings — the sand will be mixed dense and strong to resist 
the great pressure and heat; in lif/ht moulds it will be 
more porous and weak. In the first case more, in the 
latter less, venting will be required. In heavy moulds 
more, in light moulds less, coal dust will be used; because 
the burning action is more intense in the former than in 
the latter, the action of the hot metal being continued 
longer in the case of the first than in that of the second. 
In a heavy mould, the proportions of coal dust may be 
one to six or eight of sand; in light moulds it may be one 
to fifteen of sand. The reason of its use is as follows: 

Molten metal slightly fuses the surface of sand with 
which it comes into contact, and the casting becomes 
roughened in consequence. A perfectly refractory sand 
cannot be employed, there must be a certain percentage 
of alumina and metallic oxides, which are binding ele- 
ments, present, to render it coherent and workable, and 
these happen to be readily fusible. The more silica pre- 
sent in a sand the more refractory it is; but too large a 
percentage of this in a moulding sand would diminish 
its necessary cohesive property. The facing sand there- 
fore is introduced into a mould to supply that which is 
lacking in the main body itself, and by forming a back- 
ing of an inch or two in thickness to the mould, pre- 
vents, by the oxidation of the coal dust, this burning and 
roughening from taking place. The carbon of the coal 
yields with the oxygen of the air, at the high tempera- 



10 PRACTICAL IRON FOUNDING 

ture of the mould, either carbonic oxide, or carbon 
di-oxide, and the thin stratum of these gases largely 
prevents that amount of direct contact of metal with 
sand which would produce burning and roughening. 
Castings become scnid-hurnt when there is not sufficient 
coal dust used to prevent surface fusion from taking 
place. 

Dry sand. — Though ordinary green sand mixtures can- 
not be dried and yet retain coherence, mixtures of close 
heavy sands are made, which when dried in the stove, 
are comparatively hard and firm. Only the heavier sands 
of close clayey texture will bear drying: green sand mix- 
tures would become friable and pulverize under the 
action of heat. There is a superficial or skin drijing prac- 
tised with these. But that only affects the surface, and 
is quite distinct from the drying to which the present 
remarks have reference. Horse manure, cow hair, or, 
straw are mixed with dry sand to render its otherwise 
close texture sufficiently open for venting: the un- 
digested hay in the manure becoming partially car- 
bonized during the drying of the mould, while the 
moisture also evaporates at the same time. Coal dust 
is added to dry sand mixtures as to green sand. It is 
said to be strong to distinguish it from weak or green 
sand. It is a mixture which is used for a better class 
of moulds than green sand. It is also specially adapted 
for heavy work. Less gas is generated by the use of 
dry than of green sand, and the mould is, therefore, 
safer. It is mixed damp, and rammed like ordinary 
facing or moulding sand, but is dried in the core stove 
previous to casting. Being dried, it is hard, and will 
stand a greater degree of liquid pressure, approximating 
in these respects, and in being mixed with horse manure, 



SANDS, AND THEIB PREPARATION 11 

to loam. But it differs from loam in containing coal 
dust, and in being rammed damp, like green sand, around 
a complete pattern. 

Core sand. — This is variously mixed. For light and 
thin castings it is open and porous, being chiefly or 
entirely moulding sand, and having just sufficient co- 
hesiveness imparted to it by the addition of clay water, 
peasemeal, beer grounds, or other substances, to make it 
bind together. But for heavy work, and that which has 
to stand much pressure, strong dry sand mixtures, 
having horse manure, are used. It is always rammed 
damp, like moulding sand, and dried similarly to dry 
sand moulds. Cores are also made with loam by sweeping 
up or striking up. 

Loam. — This is a mixture of clayey and of open sands 
ground up together in proportions varying with the 
essential nature of those sands. It is a strong mixture, 
which is wrought wet, and struck up while in a plastic 
condition, and being afterwards dried, forms a hard, 
compact mould. The close texture of the loam is not 
vented, as is usual with green and dry sand moulds, with 
the vent wire; but certain combustible substances are 
mixed and ground up with the sand, and these, in the 
drying stove, become carbonized, leaving the hard mass 
of loam quite porous. The material usually employed is 
horse manure, containing, as it does, a large proportion 
of half digested hay. Straw, cow hair, and tow are also 
employed ; but the horse manure appears to be almost 
universally made use of. Loam is used in different 
grades, being coarser for the rough sweeping up of a 
mould, and for bedding-in the bricks, than for facing and 
finishing the surface. Old loam, that is, the best un- 
burnt portions stripped from moulds which have been 



12 PRACTICAL IRON FOUNDING 

cast in, is also ground up again with new sands, and 
used both in loam and dry sand mixtures. Loam, unlike 
the other mixtures, has no coal dust mixed with it. 

Parting sand. — This is burnt sand, used for making 
the joints between sections of moulds, which, without the 
intervention of the parting sand, w^ould stick together. 
The sand is red sand, baked, or brick-dust, or burnt sand 
scraped from the surface of castings. A thin layer only, 
of no sensible thickness, is used. Its value consists in its 
non-absorption of moisture, so that it forms a dry, non- 
adhesive stratum between damp and otherwise coherent 
faces. Parting sand is simply strewn lightly and evenly 
over with the hand. 

I have not given definite proportions of sands for 
different mixtures, because the proportions of such mix- 
tures must depend entirely upon locality as well as upon 
the class of work for which they are intended. The red 
sand or the yellow sand of one locality will not be pre- 
cisely like that of another, and therefore the practice 
will differ in different parts of the country. Moreover, 
the mixture of sands, like that of metals, is largely a 
matter of individual opinion and experience; each 
foundry foreman follows the practice which in his ex- 
perience has produced the best results. And again, green 
sand, dry sand, and loam mixtures are each prepared in 
various grades to suit different classes of work, differ- 
ences of strength or body being required, not only in 
distinct moulds, but even in individual portions of the 
same mould. As generally indicative only of the methods 
and proportions of mixing adopted, a few recipes are 
given in the Appendix. 

Facings. — The use of facing sand is not sufficient alone 
to ensure a clean face or skin on castings. Hence a thin 



SANDS, AND THEIR PREPARATION 13 

film, a facing, or a paint of a carbonaceous substance, is 
always brushed over moulds, excepting those intended 
for castings of the roughest possible character. This 
film will be laid on wet or dry, according to the class of 
work. It is comprised of different ingredients also. 
Formerly the facings or paints were mostly made of 
ground wood-charcoal and coal-dust. At that time the 
moulder mixed his own facings to suit different kinds of 
work, and the muslin blacking-hag was in frequent re- 
quisition. Now, various preparations are ground and 
mixed, and sold under different names, for specific pur- 
poses. In the best foundries now, also, nearly pure 
plumbago or black-lead is used almost exclusively. 
Though costly, it produces a finer skin than the prepara- 
tions of charcoal and coal-dust, and is less troublesome 
to apply. It is dusted over the mould, and swept with a 
broad camel-hair brush, and then sleeked with the 
trowel. On green-sand moulds nothing more is required, 
because the porous face of the sand retains the plum- 
bago. But on all dried- sand and loam moulds, and on 
the faces of skin-dried green-sand moulds, the plumbago 
is made into a wash with water and clay, or other 
cementing substances. But on moulds of this kind, the 
paint, as it is called, is generally made of the cheaper 
coal-dust mixed into a black wash or wet blacking, with the 
clay water, the clay in the water binding the dust and 
preventing it from fiaking off' when in the stove. Since the 
best plumbago costs something like dBl per cwt., or about 
twenty times as much as coal-dust, there is reason for such 
economy. It, however, always peels better than the coal- 
dust or charcoal-dust — that is, the sand can be stripped 
from the casting more freely, leaving a smoother face, 
hence for good work it has superseded the common blackings. 



14 PRACTICAL IRON FOUNDING 

There is much difference in the cost of foundry black- 
ings, the price increasing with the amount of pure black- 
lead present. All grades are obtainable, for green sand 
and loam, for light and fancy work, and for general and 
heavy work. 

There is no need to use a large quantity of blacking 
or plumbago on a mould. It tends to roll up before the 
metal, and form streaky lines or rough patches, which 
are unsightly. Neither should it be sleeked much, for 
much sleeking is always injurious to the face of a mould. 
Passing the trowel over it once or twice only lightly is 
sufficient to make it lay to the mould. It is put on dry- 
sand and loam moulds after they have been dried in the 
stove, and while yet warm. If the moulds are allowed to 
get cold first, then the blacking must be dried off. 

The effect of the blacking is to prevent the metal from 
being roughened by direct contact with the sand. The 
plumbago facing acts so efficiently that often when a 
casting is turned out, if the fingers are rubbed on it, the 
plumbago adherent to its surface will come off on the 
fingers, showing that it has remained unaffected by the 
heat. This protection has nothing to do with the pro- 
duction of sound castings, but it improves the appear- 
ance immensely. 

Chemistry of sands. — The time has not arrived when 
chemical analysis can displace the practical knowledge 
gained by experience in working in particular grades of 
sands. Analysis safely asserts that the purest sands 
should consist of little besides silica and alumina, the 
first the refractory element, the second the bond. Lime 
and iron oxide, with the alkalies — soda, potash, and 
sometimes traces of other ingredients — all detract from 
the value of a sand, lowering the fusing point and ren- 



SANDS, AND THEIR PREPARATION 15 

dering it liable to flux. If the materials in a sand 
become fused by the molten metal the result will be 
the closing of the pores, so preventing the escape of the 
gases. 

Sizes of grains. — If the grains are large and regular 
in size and shape the sand will be more porous than 
with opposite conditions. The popular objection to large 
grains is that they will not produce castings with smooth 
skins. Also grains of equal size and of angular shapes 
favour porosity, while grains of unequal sizes, and which 
have smooth surfaces, do not, though they give a strong 
sand. 

Alumina or clay, being hydrated silicate of alumina, 
contains 46.4 per cent, of silica, 39.7 per cent, of alumina, 
and 13.9 per cent, of combined water, so that the total 
silica is a larger quantity than the free silica. 

Mechanical analysis deals with the sizes of sand grains, 
and is very useful because it reveals the texture of the 
sand, which is passed through a succession of sieves of 
different meshes, and the proportions which pass through 
the different meshes afford data for estimating the suit- 
ability of the sand for fine and coarse work. Weak sands 
are fine grained and usually have least alumina. They 
are used for light green sand work. For heavy green 
sand work a larger proportion of alumina is desirable, 
and coarser grained sands. For dry sand, loam, and 
cores, the largest proportion of alumina is suitable, and 
fine sand. That castings with smooth skins cannot be 
obtained from coarse sands is negatived by experience. 
The coarse grains favour the escape of the gases, and 
the applications of facings till up the spaces against 
which the metal is poured. The following are analyses 
of standard sands used for different kinds of work. 



16 PRACTICAL IRON FOUNDING 

Sand for fine castings 

Silica 81.50 per cent. 

Alumina 9.88 ,, 

Iron Oxide 3.14 ,, 

Lime 1.04 

Magnesia 0.65 ,, 

(Fine grain) 

Sand for avawjc castings 

Silica 84.86 per cent. 

Alumina 7.03 ,, 

Iron Oxide 2.18 

Lime 0.62 

Magnesia 0.98 ,, 

(Medium grain) 

Sand for hcavij castings 

Silica 82.92 per cent. 

Alumina 8.21 

Iron Oxide 2.90 

Lime . 0.62 

Magnesia O.OU 

(Coarse grain) 

But Heinricli Eies has stated that there is no relation 
between the bonding power and plasticity, and the per- 
centage of alumina, as determined by chemical analysis. 
He says that the mechanical analysis affords an approxim- 
ate index of the cohesiveness of sand. In this analysis the 
grains, being passed through sieves of different mesh, 
yield percentages of the grains retained in each, while 
the clay group forms another percentage separated from 
the sand grains. 

The texture of a sand has a much greater influence 



SANDS, AND THEIB PBEPABATION 



17 



on its suitability for a given class of work than the 
chemical analysis. Heinrich Kies illustrates this fact 
by giving four sets of chemical and mechanical analyses 
of sands, as below. In these Nos. 1 and 2 agree closely 
in their chemical composition, but differ in their texture. 
Nos. 3 and 4 agree closely in chemical analysis, but differ 
widely in mechanical analysis. No. 1 was Albany sand 
used for stove plate work. No. 2, stove plate sand from 
Newport, Ky. No. 3, sand for general work from Peters- 
burg, Va. No. 4, sand for general work from Fredericks- 
burg, Ya. 

Chemical analyses 





No. 1 


No. 2 


No. 3 


No. 4 


Silica .... 


79.36 


79.38 


84.40 


85.04 per cent 


Alumina . . 


9.36 


9.38 


7.50 


5.90 „ 


Ferric Oxide 


3.18 


3.98 


2.52 


3.18 




Lime .... 


0.44 


1.40 


0.06 


0.06 




Magnesia . . 


0.27 


0.54 


0.21 


0.14 




Potash . . 


2.19 


1.80 


1.29 


1.65 




Soda .... 


1.54 


1.04 


0.65 


0.83 




Titanic Oxide . 


. 0.34 


0.44 


0.44 


0.78 




Water . . . 


. 2.02 


2.50 


1.49 


1.57 




Moisture . . 


0.74 


0.80 


1.76 


1.11 





Size Mesh 

20 . 

40 . 

60 . 

80 . 

100 . 

250 . 

Claj . 



Mechanical analyses 
Per Cent. Retained 



1. 

0.26 
0.51 
2.53 
0.99 
4.19 
79.85 
11.24 



2. 

0.06 
0.12 
0.32 
0.16 

0.83 
23.38 
24.73 



3. 

0.09 
0.41 
2.21 

2.67 
17.37 

58.20 
19.02 



4. 

0.19 
0.19 
0.39 
0.19 

0.98 
81.92 
15.97 



18 PRACTICAL IRON FOUNDING 

Other materials. — Small quantities of certain very es- 
sential articles are used in foundries, as clay, resin, 
flour, oil, tar, straw, hay, tow, etc. The use of the 
first three is chiefly that of cementing agents for cores. 
Small cores are cemented with these, the resin and 
flour binding the sand together, beer grounds and mo- 
lasses being used for the same purpose. Specially pre- 
pared *' core gums," the elements of which are only 
known to the manufacturers, are sold. Clay, mixed 
with water to various degrees of consistence, is a valu- 
able cement for sticking the joints of cores together; 
for swabbing flasks, the better to retain the sand; for 
cementing broken edges of moulds and cores; for mix- 
ing with wet blacking; and for other purposes. Oil is 
used for pouring over the faces of chaplets, over the 
damp mended- up parts of moulds, and around metallic 
stops in order to lessen the risk of blowing occurring in 
those localities, the metal lying more quietly on the oil 
than on the bare metal or on the moist sand. Tar is 
used for painting over the ends of wrought-iron arms or 
shafts around which metal has to be cast, and for paint- 
ing loam patterns to harden their surfaces. Straw and 
hay are used for cores, being first spun into bands, 
which are then wound round the core -bar. These are 
usually spun in the foundry, but can also be purchased 
ready for use. Tow is wound round those portions of 
bars where the spun bands w^ould be too thick. Hay is 
also used in layers in cinder beds to prevent the sand 
from filling up the interstices of the cinders. 

Sand preparation. — To prepare and mix sands various 
methods are made use of. For the floor sand, simply 
moistening with water and turning over two or three 
times with the shovel suffices in most shops. But all 



SANDS, AND THEIR PREPARATION 19 

facing sands have to be thoroughly pulverized and passed 
through sieves of varying sized mesh, according to the 
class of work for which they are required. Sand as it 
comes from the quarry is gritty and lumpy, and is 
riddled to separate the lumps, which are either thrown 
aside, or ground and crushed and re-riddled. The suit- 
able mixtures of sand and coal-dust having been made, 
they are thoroughly intermixed with water, and are then 
ready for use. 

In reference to the watering, it is as well to remark 
that this must not render the sand tvet, which would 
spoil any mould in which it might be used, but only 
moist, or damp, rendering it sufficiently coherent for 
moulding into. So that if a portion of such sand is 
taken up in the hand and squeezed, it will retain the 
impression imparted without falling apart of itself, 
which perfectly dry sand would do. 

Machines. — The growth of machinery for dealing with 
sands has been very rapid in recent years. Old methods 
have been extended, new ones have been introduced. The 
scores of designs made may be roughly classified under 
four heads : Machinery for sand drying, for grinding, for 
disintegrating, and for riddling and sifting. 

Machines for sand drying are of cylindrical form, of 
rotary designs, in which the wet sand fed in at one end 
through a hopper is conveyed to the other, the cylinder 
being disposed at an angle with the horizontal. During 
its passage it is subjected to a current of hot air. Several 
tons of sand can be treated thus daily. 

Machines for grinding sand are usually of the type 
employed for grinding loam. This is essentially a mortar- 
mill, having two heavy grinding rollers, plain or grooved, 
between which and the bottom of the pan the materials 



20 



TEAGTICAL IRON FOUNDING 



are crushed and ground. The rollers rotate on their hori- 
zontal axes, and either the rollers, or the pan, revolve 
on their vertical axis, either being driven by bevel gears. 
Sands are ground dry, and loam wet in these machines. 
The pan is emptied by opening a door in the side near 
the bottom. 

In the disintegrating machines the sand is knocked 
about between rapidly revolving prongs in the same or 




Fm. 1. — Sellers Sand Mixer. 

in opposite directions, being thrown outwards by centri- 
fugal force. Early machines were the Schiitze and the 
Sellers. Later ones more often have two sets of prongs, 
in which both sets may revolve, each in an opposite 
direction to the other, or one may revolve and the other 
be fixed. The speed of revolution is very high, and 
lumps are broken up effectively. 

T](C Sellers mud-mixinff maeliine (Fig. 1) operates 
centrifugally. The machine is circular, and the sand, 



SANDS, AND THEIR PREPARATION 



21 



on being thrown in through a hopper, A, falls among 
a number of vertical 
prongs standing up from 
a revolving plate, B. 
The prongs prevent the 
passage of stones, and 
disintegrate the sand in 
its passage outwards. 
By the covering plate, 
C, it is thrown to the 
ground beneath. The 
driving of the vertical 
shaft is done by belt 
pulley, set either above 
or below the machine, 
as most convenient, or 
by electric motor as in 
the Fig. The rate of 
revolution of the shaft 
is about 1,200 revolu- 
tions per minute. The 
hopper is hinged, and 
can be thrown back when 
necessary for the re- 
moval of obstructions. 
There is but little differ- 
ence between Schiitze's 
sand-mixer (Fig. 2) and 
that of Messrs. Sellers. 
In this mixer, vertical j^^. 2.— The Schutze Mixee. 
prongs on a rapidly re- 
volving plate, B, break up the sand falling through the 
hopper by centrifugal force. A is the hopper, C the 





22 



PRACTICAL IRON FOUNDING 



shaft driven by a pulley, IJ. An indiarubber guard round 
the machine throws the sand downwards. The hopper 
and cover (attached to each other) can be thrown back 
on a hinge to expose the plate, B. 

Fig. 3 illustrates a horizontal class of disintegrating 
mixer with double cages rotating in opposite directions, 
driven by separate pulleys. The hollow shaft which 
carries one cage runs in dust-proof ball-bearings, and the 
inner shaft is fitted in ring-oiling white-metal bearings. 




Fig. 3. — Double Cage Disintegrator. 



The sand is fed in through the shute at the side, and the 
hood is hinged to enable it to be thrown back for clean- 
ing purposes. The machine is constructed by Messrs. 
Alfred Gutmann, A.G. 

In mixing sand we seldom find moulders using 
weights or legal measures. It is always measured in 
"barrows," " sieves," " riddles," "buckets " — those being 
the utensils in common use in foundries. 

The mixing is done by hand riddles and sieves, or by 
mechanisms. The first are employed in small shops. 



SANDS, AND THEIR PREPARATION 23 

The only difference between a riddle and a sieve is one of 
size of mesh. Both alike are circular, but while riddles em- 
brace meshes down to yV ii^-? sieves cover sizes below 
these. A screen is used only to separate the coarse lumps 
from the sand at the time of delivery from the quarry. 

The sand is intermixed, riddled, or sieved by hand 
upon a rude horse formed of wrought-iron bars. The 
riddle or sieve is thrust backwards and forwards, along 
the top bars, the sand falling on the ground below, whence 
it is removed to the heaps, or to the sand bins, which are 
large recesses conveniently prepared somewhere in the 
sides of the shop for the storage of sand in readiness for 
the moulder. All the sifting and wheeling away is done 
by the moulders' labourers. There are several good 
mechanical sifters in use in foundries, operated by power 
mechanism, which imparts a rocking motion to the 
sifters. 

The swinging sand sifter (Fig. 4, shown in plan and 
in elevation), made for driving by power, is suspended 
from the beams of a roof or floor above by loosely hung 
sling rods. The parts are as follow : A is the tray itself, 
formed of a piece of ^V i^- plate bent round to form 
three sides of a rectangle, the fourth side being open. 
There are three rows or tiers of \ in. round bars riveted 
across, so pitched out that the rods alternate with one 
another in the vertical direction the better to assist in 
breaking up the larger lumps oi sand. Over the lower row 
is laid the sieve bottom (not shown in this figure), the 
size of the mesh of which may vary from |^ to 1 in. 
Screwed stay rods pass across from side to side, and by 
means of those which come near the ends, the straps, B, 
are fastened, to which the sling rods, C, are hooked. The 
oscillatory motion is imparted by means of the three teeth, 



24 



PRACTICAL IRON FOUNDING 



D, thrusting against the pins in the slotted piece, E. F, F^ 
are the fast and loose pulleys for driving, having their 




Fig. 4. — Swinging Sand Sifter. 



shaft bearings in the bracket, G, bolted to a wall, or as 
convenient. The tray is suspended at a slight angle, 
the open end, or that farthest from the driving gear, 



SANDS, AND THEIR PBEPABATION 



25 



being lowermost. The fine sand then falls vertically down- 
wards through the sieve into a bin, while the larger 
lumps pass onwards and fall out at the open end. 

Many sieves are of double design, with the primary 










■ y '-- rt>// / ' / ^y ■ 'y / // /y ^ - ' ' '' y V,V / , 



Fig. 5. — Combined Grinder and Sieve, 



object of dealing with old or floor sand. Two rectangular 
sieves, an upper and a lower one of coarser and finer 
mesh respectively, separate lumps, nails, and particles of 
iron from the sand and discharge it, while the fine sand 
is dropped through the lower sieve and discharged at 



26 



PBAGTICAL IRON FOUNDING 



one end. The sieves are set at an angle in opposite 
directions. 

Another design of sieve is rotary in action, and poly- 
gonal in outline, with a rapping device to assist the dis- 
charge. Each of these designs occurs in several modifica- 
tions. 

For grinding coal for facing sands, and blackening, a 
mill of another type is used; this is sometimes a revolv- 
ing cylinder, rotating with its longitudinal axis in the 
horizontal position, having loose heavy rollers inside. 



^^^ 




Fig. 6. — Plan View of Combined G-rinder and Sieve. 



which, as the cylinder revolves, remain in the bottom by 
reason of their weight, and crush the coal or coke, intro- 
duced before the mill is started through a door at the 
top of the cylinder. An improved form is one in which 
heavy balls are set revolving within a pan in an annular 
groove, a vertical spindle passing through the cover. The 
spindle is driven through bevel wheels by a belt-pulley. 
There is a cover of wood for the introduction of the coal, 
and to prevent the flying out of the dust. The ground coal 
is taken away through a door in the bottom of the pan. 



SANDS, AND THEIR PREPARATION 27 

A combined type of machine is seen in Figs. 5 and 6, 
comprising an edge-runner grinding pan, and an octa- 
gonal sieve, the rollers of the first named being driven by 
the bevel gears on the top shaft. The sieve is revolved 
by a belt pulley from the same shaft. When the rough 
lumpy sand has been ground in the pan, it passes down 
a sliute into the sieve. If it has been ground sufficiently 
small it falls through the meshes and is removed; but if 
there are lumps of too large a size, they are carried up 
around the top of the sieve, and fall down the top shute 
into the pan again to undergo further crushing. 

Fig. 7, PI. I, represents an electro-magnetic separator 
in conjunction with a reciprocating sieve, built by the 
London Emery Works Company. The rough sand is fed 
into the hopper at the top, and falls on to the magnetic 
drum which abstracts and retains all the nails and other 
scraps of iron or steel present, after which the sand drops 
into the sieve, and is thoroughly shaken and broken by 
the rapid reciprocations until it is fine enough to escape 
through the meshes. 



CHAPTEE III 

IRON MELTING AND TESTING 

Cast iron owes its value as a material of construction to 
the fact that it is not pure metal. If it were pure, it 
would be useless for the purposes to which it is now 
applied. Pure iron cannot be melted to fluidity, neither 
when cold is it rigid nor hard, but ductile and soft by 
comparison with commercial iron. Cast iron does not 
contain more than 93 or 94 parts of pure metal in the 
100, the remaining 6 or 7 consisting of carbon, silicon, 
phosphorus, sulphur, and manganese, with occasional 
percentages of arsenic, titanium, and chromium. 

The element which more than any other influences the 
physical character of cast iron is carbon, and this occurs 
in allotropic forms, either as graphite or plumbago, in a 
state of mechanical admixture, forming gray iron; or as 
combined or dissolved carbon, producing white iron. In 
most, if not all commercial irons, the carbon occurs in both 
forms. The proportion of combined carbon is never more 
than a mere trace in the gray, while the white iron 
is almost destitute of graphitic carbon. The mottled 
varieties occupy a position midway between the gray and 
white, and are to be regarded as mixtures of the two 
kinds, the mottle being more pronounced as the propor- 
tion of white increases. Here, too, the proportions of 
combined and graphitic carbon become nearly equalized. 
Gray iron is the most fluid, but is the weakest. White 

28 



IRON— MELTING AND TESTING 29 

iron runs pasty, and is strong, but brittle. Mottled iron 
melts very well, and is both strong and tough. 

Iron is adapted for general engineers' work in propor- 
tion to its amount of mottle, highly mottled iron being 
correspondingly prized by foundrymen. 

There are several varieties of pig supplied by the iron- 
masters, ranging from the No. 1 Clyde, which is the 
grayest iron, to the forge pigs, which are white irons 
(see the Appendix). Hence it is possible to obtain pigs 
suited to almost any class of work, being either used 
alone, or by intermixture. In foundries where the same 
class of castings is being constantly turned out, this is 
what is done; but in general foundries, where all kinds of 
castings are required in gray, white, and mottled iron, in 
all their grades, usually three or four kinds of pig only are 
kept in stock, and the numerous grades of metal required 
from day to day, or during the same day, are prepared 
by admixture of pig with scrap. It is in these mixtures 
that the skill of the practical foreman or furnaceman is 
seen, skill which comes only after long experience. There 
are many moulders who would not know how to mix 
metals to produce definite grades, and no rules can be 
laid down for this work except those of a somewhat 
general character. Thus it is easy, having ascertained 
the metal which results from the mixture of certain pigs 
in certain definite proportions, to repeat the operation as 
often as required, since a grade of pig of a given brand 
is fairly though not absolutely constant in character. 
But when scrap is used, the quality of each separate piece 
of scrap has to be estimated by its behaviour under the 
sledge, and by the eye. The use of scrap, if purchased 
judiciously, and mixed by a competent man, is more 
economical than that of pig, and there is therefore 



30 PRACTICAL IRON FOUNDING 

advantage in its employment. Every furnaceman and 
foreman should therefore learn to judge of the quality of 
scrap and pig, and the effect of their intermixture. After- 
wards he may test the results experimentally at the testing 
machine; but he must know how to mix, or the testing 
machine will record only failures. 

Gray iron on being struck with a sledge fractures easily, 
and presents a highly crystalline structure, with a some- 
what dull bluish-gray metallic lustre. If very dull, the 
metal is inferior, and poor in quality. 

Iron follows the same law of crystallization as other 
substances. The slower the rate of cooling the larger the 
crystals produced. If a newly fractured surface of gray 
iron is shaded by the hand, and so viewed with reflected 
light only, the crystals of graphite become visible, appear- 
ing as black lustrous patches amongst the iron. If a 
portion of the iron is crushed and levigated, the graphite 
will float on the surface of the water. When the metal 
is molten it lies quietly in the ladle, breaking into large 
striations, without sparks or disturbance. After standing 
awhile it becomes covered with scum, composed of scales 
of graphite which have separated and floated to the sur- 
face. When cast, it runs fluid, and takes the sharpest 
impressions of the mould, being thus adapted for the 
finest castings. It is only moderately contractile. At the 
testing machine it breaks with a very moderate load, 
undergoing however a considerable amount of deflection 
first. It can be tooled easily. 

If we take wldte iron, whether in the form of pig or of 
scrap, and fracture it, we find that it requires more force 
than the gray to effect fracture, but that it breaks very 
short and clean. An inspection of the fractured surface 
reveals a highly crystalline structure, but the crystals are 



IRON— MELTING AND TESTING 31 

long, fine, and needle-like in character, and of a bright, 
almost silvery-like lustre: no scales of graphite can be 
detected. The melted metal when in the ladle, though 
thick and somewhat viscous by comparison with gray 
iron, is in a state of violent ebullition; boiling, bubbling, 
and throwing off a quantity of sparks or jumpers. It does 
not run well except in considerable mass, and is highly 
contractile. Unlike the gray iron, it cannot be shaped 
with the chisel and file. At the testing machine it sus- 
tains a greater load before fracture than gray iron, but 
breaks with less deflection. 

The mottled iron being a mixture of gray and white, 
partakes more or less of the characteristics of each, and 
is therefore better adapted for most castings than either 
of those alone. Considerable force is required to fracture 
a good sample of mottled iron, and when the broken 
surface is examined it presents that peculiar mottled 
appearance from which it derives its name. The crys- 
tals are of the same form as those in gray iron, but 
smaller, and the dull bluish lustre of that is replaced by 
a more silvery hue. The colour alternates, being patchy, 
the white contrasting with the graphitic scales still pre- 
sent. It melts and runs well, is tolerably quiet in the ladle, 
is moderately contractile, takes a high strain and a good 
deflection at the machine, and tools with average ease. 

There are several grades of gray, mottled, and white 
irons, and the skill of the furnaceman consists in judg- 
ing of the minute differences in these and utilizing them 
accordingly. 

There is a grade of iron often found along with scrap, 
known as burnt iron. It is metal which, having been 
long subjected to an intense heat below the melting 
point, has lost much of its metallic character, being 



32 PRACTICAL IRON FOUNDING 

largely in the condition of oxide. It is of an earthy red 
colour, and is found in scrap containing old fire bars, 
sugar and soap pans, retorts, and furnace grates. In the 
furnace it does not melt freely, but becomes viscous or 
pasty, and chokes the tuyeres and the fuel. In a furnace 
using much of this, the slagging hole has to be kept open 
during nearly all the time of melting, and much of the 
iron mixes with and runs away to waste with the slag. 
It damages the furnace lining, and when poured runs 
very thick, and produces almost white, but rotten cast- 
ings. Burnt iron can only be properly utilized by ad- 
mixture in slight proportions with good open gray pig. 

The largest proportion of pig used for foundry pur- 
poses is smelted either in Scotland from the Black Band 
ironstone; or in the Cleveland district in the North Bid- 
ing of Yorkshire, from the Cleveland ironstone. Smaller 
quantities come from Shropshire, Staffordshire, South 
Wales, and a few other localities. 

Pig is obtainable in five or six grades. No. 1 is the 
most gray and open, and as the numbers run up the iron 
becomes closer and mottled, or white. 

Scrap, — When a furnaceman or foreman has to pro- 
vide for a general run of work, as is the case in nearly 
every foundry, there are usually two courses open. One 
is to stock various brands of pig and melt from those 
brands, singly or variously mixed, to suit the various 
kinds of work on the floor. Thus, for cylinders and for 
liners a different quality will be required from that for fire- 
bars or ploughshare points, or, again, for machine fram- 
ings or gear wheels. Though each grade may be melted 
on the same day, in the same cupola, the difi'erent mix- 
tures required will be kept apart in the cupola. The 
ironmasters will send pig of any given quality, suitable 



PLATE I 




See p. z I 



Fig. 7. — Combined Separator and Sievj 




Seep. 63 [Facing p. S2 

Fig. 18. — Roots' Blower, Motor driven 



inON— MELTING AND TESTING 38 

for any class of work. Or, without a very large stock of 
different brands, a furnaceman who knows his business 
can, by judicious mixing, with or without remelting as 
occasion requires, make up metal to suit any job. At the 
two extremes there are the soft open gray, and the hard, 
close white pig. Between these there comes every variety 
of gray, mottled, and white. But in all foundries a cer- 
tain proportion of scrap is used along with the pig for 
most classes of work. A furnaceman or foreman who 
thoroughly understands the mixing of scrap and pig is a 
valuable acquisition to a firm, for he can not only improve 
the quality by such mixture, but can save much money 
also, because scrap is often to be bought at a cheaper 
rate than pig. There is this further advantage, too, that 
scrap has been remelted once at least, and therefore the 
cost of such remelting — supposing pure pig would other- 
wise have to be used and remelted — is saved. Further, 
metal is improved by the mixing of several kinds of pig 
and scrap, very much as hammered scrap is improved by 
the piling and welding of all kinds of bars. 

Only when a furnaceman cannot judge scrap well, is it 
desirable to make use chiefly of special brands of pig. 
There must be some scrap always used, because the 
runners and risers, the overflow metal, and the wasters 
have to be used again in any foundry. And there are 
few foundries that do not use one-third or one-half scrap 
in the mixing of metal. 

Good stocks of pig and scrap should be laid in when 
iron is cheap. Much money can be saved by watching 
the markets, and purchasing heavily when prices are 
low. A look-out should specially be kept for good 
cheap scrap. A competent man should be sent to see 
it previous to purchase. Water and gas pipes are 

D 



34 PRACTICAL IRON FOUNDING 

about the worst scrap, old engine work and machinery 
the best, and the older it is, almost invariably the better 
it is. The scrap should be roughly sorted out according 
to quality, and kept in separate heaps. 

The quality of pig, though subject to slight variations 
in the same consignment, is sufficiently well known, and 
there is little need to look at every bar as it is broken. 
Not so with scrap. Every piece of this must be judged on 
its own merits. This is a rather tedious process, and 
there is only one way in which it can be done, and that 
is by the character of the fracture. The opinion is formed 
partly by the amount of work it takes to break a given 
piece, which is a measure of its strength and toughness; 
and partly by the appearance of the fractured surface, by 
which the nature of the iron is apparent. The broad ap- 
pearances of gray, mottled, and white irons are familiar 
to most; the furnaceman's skill lies in judging of minute 
variations in these broad differences. As a rule, the 
rougher and more uneven and exfoliated the aspect of the 
fracture, and the more metallic the lustre, the stronger is 
the iron. If a mass of iron has draws in it, that will in- 
dicate that the iron was of a strong nature, but was not 
properly fed. If an iron breaks off short, and is dull in 
appearance, and the crystals open, it is weak and poor. 
Gray weak iron can be made stronger by the addition of 
white or mottled; and mottled can be brought back to 
gray by the addition of open No. 1 Scotch pig, or stove 
scrap. Weak iron can be strengthened by once or twice 
re-melting. Test bars afford a valuable aid in estimating 
the quality of a mixture that is required for very specific 
purposes, and by their aid the foreman is enabled to keep 
a constant check on his experimental mixtures. 

Eepeated re-melting of gray iron tends to increased 



IRON— MELTING AND TESTING 35 

strength, at the sacrifice of toughness and elasticity; the 
re-melted metal approaching to the white condition. 
Hence, after two or three re-meltings, more open pig 
should be added to preserve the toughness of the metal. 

It is by admixture therefore that nearly all the grades 
of cast iron for foundry service can be obtained. The 
difference in the qualities of these mixtures is, as we 
have stated, due largely to the amount and manner of 
occurrence of carbon. In reference to the remaining con- 
stituents of commercial pig, and the question of their 
relative influences upon the metal, it will be sufficient to 
note very briefly the leading facts which the founder 
should know in relation to these, and then pass on to 
the tests applied to cast w^ork. 

Silicon is one of the most valuable elements found 
associated with cast iron. Formerly it was regarded as 
an enemy, producing brittle and poor metal. Now, by 
mixing certain proportions of silicon with white iron, it 
is converted into gray, the silicon throwing out carbon 
from the combined to the graphitic condition. 

Pliosj^Jwrus is always present in pig, and does no harm 
so long as it does not exceed 0*5 or 0*75 per cent.; a 
higher proportion tends to brittleness. Phosphorus how- 
ever renders iron fluid, and this is an advantage for 
small castings, but at the same time it renders them 
hard. 

Sulpliur in small quantity produces mottled iron, 
separating carbon as graphite, but in excess it causes the 
iron to become white. 

Manganese is undesirable, producing a w^eak and white 
iron. 

Aluminium. — It has long been known that a very 
small percentage of aluminium, so little indeed as *01 per 



36 PRACTICAL IRON FOUNDING 

cent., suffices to render molten wrought iron very fluid, 
and to prevent blow holes in steel castings. It is equally 
beneficial in cast iron. 

It causes iron at the instant of solidifying to throw out 
a portion of its combined carbon into the graphitic con- 
dition, producing gray iron. The formation of the gra- 
phite is also so uniform that the thin portions of the 
castings are as gray as the thicker portions. In this 
respect it resembles silicon. Since the aluminium sets 
free the carbon at the instant of solidification there is 
less tendency to chill, which result is caused by the run- 
ning of metal against a cold surface, and the consequent 
imprisonment of combined carbon before it has time to 
separate as graphite. 

When aluminium causes the separation of the carbon 
at the instant of solidification, the scales of graphite at 
the surface of the casting act similarly to blackening, 
protecting the surface from becoming sand-burnt, and 
therefore producing a softer skin for cutting tools. 

The presence of aluminium, by making the grain 
closer and finer, gives greater elasticity, and reduces the 
permanent set. 

The shrinkage of iron is lessened by the use of alumin- 
ium. This might naturally be expected, knowing, as we 
do, that gray iron is less contractile than white. It 
is a distinct advantage, as lessening shrinkage strains 
on disproportionate castings. 

Testing. — It is at the testing machine that the precise 
value of any mixture of metal made is ascertained, and 
no foundry of any pretensions can afibrd to be without 
such an instrument. Testing, in the hands of such men 
as Professors Unwin or Thurston, has become a scientific 
work, in comparison with which that of the foundry is 



inON— MELTING AND TESTING 37 

rough and approximate only. But this is nevertheless 
sufficiently accurate and adequate for its purpose. 

The common method of testing is to cast bars having 
a cross section of 2 in. x 1 in., and a length of 3 ft. 2 in. 
These are placed upon supports 3 ft. apart, the 2 in. being 
in the vertical direction, and loaded until they fracture. 
Fracture in a good bar should not take place with a less 
load than 30 cwt., in exceptional instances it goes as 
high as 33 or 35 cwt.; 25 to 28 cwt. would indicate a 
poor bar. The amount of deflection is also noted, as 
being a measure of the elasticity of the metal. It should 
not be less than | in., and will in good bars be as high 
as 2 in. The behaviour of bars cast from the same 
ladleful of metal in the same set of moulds will often 
be found to vary, fracture variously occurring within a 
range of 2 or 3 cwts.; hence it is the practice to cast 
several bars for testing, and take the average of the 
whole. Test bars should be cast from the same metal, 
under the same conditions of melting, as the work for 
which they afford the test, and should be stamped or 
labelled with the date, and all particulars deemed of 
service. They should be ca.st in the same manner as the 
work for the strength of which they are to be the index, in 
dry sand if the work is in dry sand, in green sand if that 
is in green. The relative strength of the bars is affected 
by difference in dimensions, a bar of small area being 
relatively stronger than one of larger area, the reason 
being that the chilling effect of the sand hardens the 
outer skin, and so raises slightly its tensile strength. 
That which is often now regarded as the standard bar is 
1 in. square and 1 ft. long. This sustains about one ton 
before fracture. Pounds weight on this bar divided by 84 
give hundredweights on the 36 in. + 2 in. + 1 in. bar; and 



38 PRACTICAL IRON FOUNDING 

hundredweights on the latter multiplied by 84 give 
pounds on the former. 

Testing machine. — A machine designed for making 
tensile, and also transverse tests on cast-iron specimens, 
is illustrated by Figs. 8 and 9, being manufactured by 
Messrs. W. and T. Avery, Limited, of Birmingham. The 
construction comprises a cast-iron bed-plate, with dogs 
having blunt knife-edges, these dogs being adjusted 
along to graduations on the base, either at 12 in., 
24 in., or 36 in. between centres. The base carries a 
cast-iron standard, fitted with hardened steel bearing 
blocks, upon which the fulcra knife-edges of the steel- 
yard rest. The wrought-iron steelyard is provided with 
knife-edges of hardened steel, and is graduated up to 
the full capacity by 28 lb. divisions. It is fitted with a 
sliding poise by means of which it is kept in equilibrium, 
and the strain indicated. The poise is moved along by 
turning a small wheel'on its front. The strain is put on 
by turning the hand-wheel at the top, rotating the screw, 
and actuating the stirrup that carries the blunt knife- 
edge wdiich exerts the strain on the specimen. A spring 
buffer is fitted in the steelyard carrier in order to min- 
imize the shock when the specimen breaks. A graduated 
deflection scale is provided, by means of which the vary- 
ing deflections of a specimen under different strains can 
be ascertained during the test. Two series of gradua- 
tions are placed on, one decimally by ^q in. divisions up 
to 1 in., and the other by yV ii^- divisions up to 1 in. 

Tensile specimens h in. in diameter can be held in the 
hardened steel grip wedges, for which size the capacity 
of 60 cwt. allows for iron that will stand 15 tons per 
square inch, while bars of 2 in. by 1 in. section or less 
can be dealt with on the transverse testing dogs. 




« GO 



d 



P^ 




o 

M 

H 



M 

<1 



00 

6 

M 



40 PRACTICAL IRON FOUNDING 

Testing in the hands of an experienced foundryman 
reveals a great deal. For he not only notes breaking 
strength and deflection, but also the aspect of the frac- 
tured surfaces. He observes the extent of mottle or of 
graphite, the dull or lustrous appearance, homogeneity 
of texture or the opposite condition, the tendency to 
undue hardness or softness, whereby he learns how to 
make changes in his mixtures in order to insure the 
predominance of certain qualities which he desires to 
obtain. The iron for 'nine-tenths of the castings made 
is put together in this way. Still, the test bar tells 
little of real value to one who is not acquainted with 
foundry work, and it might tell a good deal more to the 
latter if used under a better method. 

There are other incongruities in the commonly ac- 
cepted tests of bars which strike one as rather curious. 
There are a few impact tests made in England. The 
value of impact tests is not so great as in the case of 
rails, because cast iron is distrusted for live loads, unless 
the mass of metal is so enormously in excess of that re- 
quired for strength as to absorb all injurious vibration. 
Yet since most ironwork is liable to more or less of 
shock, the impact test should be of even greater value 
than a purely tensile test, or a cross breaking test. 

There is another serious drawback inherent in foundry 
tests, and it is this: Little attempt is made to measure 
the shrinkage of iron by means of test bars. Yet many 
a casting is broken in consequence of excessive and un- 
equal shrinkages. Much of this could be avoided by the 
use of iron selected with suitable reference to the nature 
of the casting. To a large extent this is done in practice 
by the observation of the open or close nature of the 
fractured surfaces of test bars, or of pig and scrap 



IRON— MELTING AND TESTING 41 

selected for making up the cast. But this is not an 
exact method, such as would be afforded by the meas- 
urement of a test bar. Some testing machines embody 
provision for the precise measurement of the shrinkage 
of test bars. The general adoption of this method would 
go far to lessen the internal stresses which frequently 
exist in castings, and which are a source of weakness, 
resulting often in serious danger. 

Further, since such great emphasis is laid by metal- 
lurgists upon the influence, injurious or otherwise, of the 
presence of small percentages of foreign elements upon 
cast iron, a very distinct advance has been made in this 
direction by Mr. Keep, of Detroit, a brief account of 
whose methods follow. Not by analysis, but through 
physical results, can the founder learn best how to grade 
his irons for their specific and varied purposes. 

The methods of testing adopted by Mr. Keep may be 
briefly summarized as follows: 

Though based on chemistry, they can be applied by 
anyone who has no knowledge of chemical reactions or 
of analysis. The basis of the system is the power which 
silicon possesses of causing carbon in iron to pass during 
cooling from the combined into the graphitic condition. 
So that, given an iron with a sufficient percentage of 
total carbon, it is possible to so vary the quantities of 
silicon added as to produce irons in which the relative 
proportions of combined and graphitic carbon shall be 
graded to suit any classes of foundry work. Mainly, 
Mr. Keep makes the shrinkage of the iron the crucial 
test. If equal shrinkages can be produced in different 
mixtures of iron, then each mixture will have similar 
qualities as regards strength, hardness, or softness. 
Moderate variations in the proportions of manganese, 



42 PRACTICAL IRON FOUNDING 

sulphur, and phosphorus are of little or no practical 
consequence, provided the combined and graphitic car- 
bons are suitably proportioned, and this is evidenced by 
the shrinkage. When silicon is added it changes com- 
bined carbon into graphite, and the casting occupies a 
larger volume than it would previously have had. All 
the founder has to do is to be sure that there is sufficient 
combined carbon for the silicon to act upon, and through. 
Silicon alone would increase shrinkage and harden iron, 
but when acting through carbon it produces an exactly 
contrary effect. 

Making the crucial test one of shrinkage is one which 
is consonant with experience. Since hard white iron 
shrinks more than soft gray iron, and since the former 
contains its carbon mainly in the combined form, and 
the latter mainly in the graphitic form, a hard iron can 
be changed into a soft one by causing the carbon to 
separate out as graphite. Silicon effects this change, 
and therefore indirectly silicon added to hard white iron 
makes it soft and gray and diminishes its shrinkage. If, 
further, uniformity of shrinkage and hardness is secured 
in several different irons by the addition of variable pro- 
portions of silicon, the irons will be all equally graded 
for foundry purposes. The larger the mass in a casting, 
other conditions remaining the same, the less silicon 
will be required, because the cooling is slower, and the 
carbon has more time to separate out as graphite. The 
more carbon present, the less silicon will be required, 
because the presence of plenty of carbon is favourable 
to the separation of graphite. 

It is not, however, that a certain percentage of silicon 
is necessary to produce a bar or casting of definite 
strength. It is its infiuence relatively to the mass, and 



IRON— MELTING AND TESTING 43 

not the exact proportion of silicon relatively to chemical 
composition, which is the essential crux of these methods. 
Irons of exactly the same chemical composition pom*ed 
from the same ladle will not produce bars of precisely 
the same strength. But the shrinkage of a casting, which 
can be controlled by silicon, can be measured, and the 
shrinkage determines the degree of crystallization, close- 
ness and uniformity of grain and texture, and therein 
lies its value. The necessary amount to be added de- 
pends not only on the percentage quantity of carbon 
present, but also, and much more, upon the mass of the 
casting. The addition of silicon retards cooling gener- 
ally, producing the separation of graphite, and diminishes 
shrinkage. The throwing out of graphite from combined 
carbon removes brittleness. If shrinkage is too great, 
increase the silicon, and rice versa. In small bars and 
castings the silicon must be high (up to 3 per cent.), and 
in large bars and castings it must be low. The reason 
lies in the difference in shrinkage. A small casting 
shrinks quickly, and therefore needs more silicon to 
throw out the combined carbon as graphite. A large 
casting shrinks slowly, and therefore requires less silicon 
to effect the separation of graphite. Without the silicon 
it is possible, and would in fact occur in extreme cases, 
that from the same metal a small casting may be white, 
one of average dimensions mottled, and a very large one 
in the main gray. 

The details of the tests are these: Bars are cast be- 
tween chills or yokes in order first to ensure absolute 
uniformity in length, and to get a chill on the ends. 
The bars are of two sizes, l^xhxh in., and 12 x 1 x yV in. 
The thin bar is used for fluidity test, because none but 
very fluid and hot iron will run the whole length of 



44 PRACTICAL IRON FOUNDING 

the bar. The experience of the moulder soon enables 
him to judge of the behaviour of metal of a given quality 
in castings of different dimensions, made from metal 
which gives certain results in a test bar. And in order 
to furnish a ready means of comparison between bars of 
different dimensions Mr. Keep has constructed an ideal 
chart for ready reference. 

Great care is taken to ensure uniform results in the 
testing, metal patterns being used on a bottom board, 
and no rapping or touching up of the mould is done. 
The length between the end faces is 12 J in. There are 
four points noted — the amount of shrinkage of the bar, 
the strength under dead load and under impact, the 
depth of chill, and the aspect of the fractured surfaces. 
The dead load and imj)act tests are conducted in auto- 
graphic recording machines. The depth of chill is ascer- 
tained by fracturing a bit out of the bar next the end. 
The chill will run from -^V ^o ii ii^- inwards, according 
to quality, and is an important element in judging the 
suitability of an iron for a given purpose. At the same 
time, the aspect of the unchilled fractured surface is 
indicative of the open or close nature of the iron. 

CJdlUnfi. — When iron is poured into metallic moulds 
instead of into those of sand, the result is that the sur- 
face of the casting so poured becomes of a steely char- 
acter, so extremely hard that no cutting tool will attack 
it, and more durable, more capable of resisting the 
action of friction, than steel itself. It is believed that 
this chilling, as it is called, takes place in consequence 
of the combined carbon in the iron not having time to 
separate out as graphite. Poor irons will not chill 
deeply. To produce chilling of ^V in. or '; in. in depth, the 
metal must be tough, strong, and mottled. A strong iron 



IRON— MELTING AND TESTING 45 

is also necessary, because there is tremendous stress in a 
chilled casting, owing to the inequality in the shrinkage 
strains in the contiguous portions, which are rapidly, or 
slowly cooled. 

The iron for chilling should not be poured very hot, 
but dull, it will then lay more quietly in the mould. The 
chill should also be heated in the stove to so high a 
temperature that it cannot be touched with the hands. 
To pour metal into a cold chill is always dangerous. The 
surface of the chill is protected with a coat of black 
wash or other refractory material. In no case should 
the metal be allowed to beat long against a localized 
spot, as burning of the chill and partial fusion of the 
same to the molten metal is certain to ensue. The mass 
of metal in a chill should be large. The chill should 
always be much heavier than the casting which has to 
be poured into it; without sufficient mass, fracture is 
almost certain to occur. 

Permanent moulds. — The experience now being gained 
with permanent moulds of metal promises economies in 
some classes of castings. If the ramming of a fresh sand 
mould for every casting could be abandoned in certain 
kinds of repetitive work, a great vista of cost-saving 
would be in sight. It has long been done in chilled 
castings; but, the chilling effect of a metal mould must 
be avoided in the general run of castings, such as it is 
desirable to produce in permanent moulds, and this 
tendency to chill is the principal difficulty met with in 
casting in these moulds. The remedy is to get the 
casting out before chill has formed. The time to be 
allowed lies within extremely narrow limits for any one 
shape or mass of casting, but it varies with different 
shapes and sizes. The chemical composition of the iron 



46 PRACTICAL IRON FOUNDING 

has also some influence. The difference between the 
chemical composition of deep-chilling, and practically 
non-chilling irons is vital, whether the grading is done by 
fracture or l)y analysis. But the non-chilling irons will 
be hardened on the surface if allowed to cool in a metal 
mould, and this hardening must be prevented. 

Castings left to cool and chill in a metal mould have 
all their carbon in the form of hard, needle-like crystals, 
provided always that the silicon is low. If the same 
castings are taken out as soon as the exterior has set, 
the carbon will distribute itself in the graphitic form 
throughout the mass. This is the reason why castings 
are removed from permanent moulds immediately they 
have set, and while still at a bright yellow or orange tint. 
An interesting fact is that a large content of phosphorus 
and sulphur, sufficient to weaken a casting made in green 
sand, has no such result in castings poured in permanent 
moulds. 

Attempts have been made, but with little success, to 
coat the interior of the metal moulds when cold with 
various substances to prevent chill — pulverized talc, or 
chalk mixed with gasolene or kerosene, and dried. 
When moulds are hot, heavy oils or paraffin have been 
used. But in the latest practice no coatings are em- 
ployed. 



CHAPTEK IV 

CUPOLAS, BLAST, AND LADLES 

Although for special purposes iron is sometimes melted 
on the hearth of the reverberatory furnace, yet for all the 
usual run of work the cupola furnace is that which is 
everywhere employed. The best cupola furnaces which 
are in use to-day differ from those of half a century ago. 
Better cupolas have been designed in some respects, 
more economical in fuel, but many, the older ones, are 
retained, chiefly, it must be supposed, by virtue of their 
simplicity, and also because, in the hands of a careful 
furnaceman, fairly good commercial results can be ob- 
tained therefrom. Before noting some of the improve- 
ments which have been made in cupolas, I will briefly 
describe one of ordinary form (Figs. 10 and 11), and of 
moderate capacity, such as may be seen in daily work in 
many foundries. 

The base A is of brick, covered with a cast-iron plate, 
B. The shell C is of boiler plate, single riveted, lined 
with fire-brick, arranged as headers, set in fire-clay. 
In small cupolas there is only one course of bricks, in 
large ones they are two courses deep. The vitrified slag 
soon forms a glassy skin over the bricks, and thus 
becomes a protective coating to them. A bed of sand, D, 
is beaten hard down on the bottom, and upon this is 
placed the bed charge, E, of coke; metal, coke, and flux 
alternating thence all the way up to the charging door, 

47 




Fig. 10. — Cupola. Elevation. 



CUPOLAS, BLAST, AND LADLES 



49 



F, which is about a couple of feet above the charging 
platform, I. The blast necessary for combustion is 
brought in at the two tuyere pipes, G, G, from the blast 
main, H, which is properly placed below the ground, as 




SECTION N— N 

Fia. 11. — -Cupola. Sections. 



shown. The metal is tapped out at the hole, J, (Fig. 11), 
the spout of which, K, is usually brought through the 
foundry wall, outside of which the cupola is properly 
placed. L is the door closing the breast hole, through 
which the fire is lit, which is closed just previous to 
the turning on of the blast, and through which the 

E 



50 PRACTICAL IRON FOUNDING 

embers are raked after the casting is done. Above the 
breast hole is the slag hole, M, placed just below the 
level of the tuyere openings. Through this the slag 
is tapped out at intervals during the process of 
melting. 

Charging. — The method of charging is as follows. First 
of all, the interior up to the height of the tuyere holes 
is lined for a thickness of f in. or 1 in. with fire-clay, or 
with loamy sand. The tap hole, J, is lined by ramming 
sand and fire-clay around a pointed bar inserted in the 
opening in the bricks. A fire is lit in the bottom, and a 
bed charge, E, of coke is laid upon this. Then follows a 
charge of iron and flux, and again a layer of coke, and 
so on alternately, as seen in Fig. 10. This is done two 
or three hours before the blast is put on, and in the 
meantime the various openings into the cupola remain- 
ing open, the fuel burns up quietly, and everything be- 
comes warmed equably throughout. When the time 
arrives for the melting down of the metal, the breast- 
plate, L, is lined with sand, and wedged in place, the 
tuyere pipes, G, the bends of which are made to swivel, are 
put into position and luted with clay, and the tap hole, J, 
being open, a gentle blast is put on for five or ten min- 
utes. This has the effect of hardening the clay in the 
tap hole. The blast is then stopped, the tap hole closed 
wdth clay by means of the bot-stick, and the full blast 
pressure is put on. In from ten to fifteen minutes the 
metal begins to run down, and presently, when the fur- 
naceman observes through the mica sight holes, H', H\ 
of the tuyeres that the metal is getting nearly to the 
level of the tuyere openings, he taps out a quantity into 
a ladle. This is done by driving the pointed end of the 
bot-stick through the hard-baked clay, giving the stick 



CUPOLAS, BLAST, AND LADLES 51 

a rotary motion with his hands, to enlarge the hole. The 
metal then runs down the shoot, K, in a steady stream, 
and when the ladle is nearly filled, the tap hole is closed 
with a dauh of clay held on the flat end of a hot-stick, 
the stick being held diagonally downwards towards the 
hole at first, and then lowered sharply until the axis of 
the stick is in line with the hole J, so closing it up with- 
out risk of spluttering of the iron. 

As the metal runs down, additional quantities of iron, 
fuel, and flux are charged in at the door, F. Slag forms 
in quantity, and this has to be tapped out at intervals 
through the slagging hole, M. The slagging will have to 
be repeated more or less often according to the inferior, 
or superior class of the metal. As long as slag continues 
to run, the hole should be left open. If very inferior or 
burnt iron is being melted the slag may be running 
nearly all the while. The economy of cupola practice is 
largely dependent on keeping the surface of the metal 
free from slag. 

Charges of metal of different kinds are melted in the 
cupola at the same time, by interposing between each 
charge a stratum of coke rather thicker than those used 
in the ordinary work of melting. The charge which is 
lowermost is then tapped out, as the charge above begins 
to melt, and the furnaceman is able to see the beginning 
of the melting of an upper charge at the sight holes, //', 7/'. 

Large quantities of metal are tapped out in detail, a 
ton or a couple of tons at a time, until sufficient has 
accumulated in the ladle. Metal in the ladle will retain 
its heat for a very long time if radiation is prevented by 
sprinkling the surface with the blowings from a smith's 
forge, and by allowing the oxide and scum to remain 
thereon. 



52 PRACTICAL IRON FOUNDING 

When the melting down is done, the whole of the fur- 
nace contents are raked out through the breast hole, or, 
if the cupola is of the drop bottom type, like Fig. 12, 
p. 55, by dropping the bottom. Under no circumstances 
can the metal and fuel remain safely in a cupola long 
after the blast is shut off, since, if it sets, the mass will 
hung up or goh up the furnace, forming a salamander, and 
the furnace lining may probably be destroyed in the re- 
moval of the obstruction. 

Economical melting, — The proper melting of metal is a 
task requiring a good deal of experience and caution. 
Economical melting is an excellent thing, but there are 
other points which have to be regarded besides the state- 
ment on paper that a ton of metal has been melted with 
a certain percentage of fuel. Iron may be melted so dull 
that poor, if not waster castings result, when a little more 
fuel \v^ould have dead-melted it thoroughly, producing 
good, sound, homogeneous castings. Then the size of the 
cupola, and the amount of w^ork being done, has to be 
taken into account. A small cupola is more wasteful in 
fuel than a large one. A cupola running two or three 
hours daily is more wasteful than one running all the 
day. Inferior iron is more wasteful of fuel than iron of 
superior quality. Hence general porportions only can be 
given for percentages of fuel. The total percentage of 
fuel to iron melted may range economically from 1-^- cwt. 
to 3 cwt. per ton, according to circumstances. Total 
percentage includes the fuel used in the bed charge. 
This always bears a large proportion to the total amount 
used, hence the reason why short meltings are so much 
more costly than lengthy casts. For a cupola like Fig. 10, 
4 ft. diameter, a bed charge, E, of 10{r cwt. is used; for 
a similar cupola, 2 It. 4 in. in diameter, a bed charge of 



CUPOLAS, BLAST, AND LADLES 53 

G cwt. is used. But the bed charge will equal about one 
half the quantity of coke required for a " blow " of 
moderate length, say of from two or three hours. 

The succession of charges in the cupolas of the two 
sizes above-named is as follows: 4 ft. cupola: bed charge 
10^ cwt.; each charge of iron 21 cwt., separated by 
2 1" cwt. of coke; \ cwt. of limestone (flux) in bed charge, 
and seven or eight pounds on each subsequent charge. 
2 ft. 4 in. cupola: 6 cwt. bed charge, each charge of iron 
14 cwt., 11 cwt. of coke in each subsequent charge. The 
first cupola will melt four tons per hour, the second from 
two and half to three tons per hour. But in the first 
cupola, with heavy casts, twelve tons can be melted with 
twenty-five cwt. of coke, including bed charges. 

In cupolas such as these, doing jobbing work, using 
different mixtures of iron, making many light casts, and 
running from two to four hours per day, the conditions 
for economy of fuel do not exist, and as much as two cwt. 
of fuel per ton of metal melted will not be an unreason- 
able proportion. Where contrary conditions exist, the 
proportions may be less by nearly one half. 

The chemical conditions which govern economical 
working are those which relate to the purity of the fuel, 
and to the complete utilization of the products of com- 
bustion. The coke should be the best and purest pro- 
curable, free from sulphur, hard, columnar, heavy, having 
metallic lustre, and clean. The height of a cupola, the 
position and number of tuyeres, the density of the blast, 
all vitally influence the ultimate results. Height is ne- 
cessary, because without it large quantities of combustible 
gas would escape unburnt and become lost. 

Comhustion. — The process of combustion is as follows: 
Air, under pressure, entering the cupola through the 



54 PRACTICAL IRON FOUNDING 

tuyeres, meets with the heated fuel. The oxygen in the air 
combines with the incandescent carbon in the fuel, form- 
ing carbonic anhydride, COo, a gas which will not burn. 
This gas takes up more carbon, becoming carbonic oxide, 
CO, equivalent to Co O2, which is combustible. If, however, 
this gas does not meet with sufficient free oxygen at a 
high temperature, it cannot burn, but will pass away, 
representing a certain number of heat units wasted. But 
if it meets with a sufficiency of heated oxygen higher up 
in the furnace, it burns, giving out heat available for 
combustion. Hence the reason why the taller cupolas 
are more economical than the lower ones. Flame at, and 
above, the charging door represents heat lost, as far as 
useful work is concerned. Hence also the reason why 
two or three rows of tuyeres, to supply the zones of oxygen 
necessary for combustion, have been adopted in nearly 
all cupolas which have been designed to supersede the 
older forms, a mode of construction which is therefore 
seen to be quite correct in principle. 

The perfect combustion of carbon to COo evolves 
14,647 British thermal units per pound of fuel. If onl}^ 
partially burned to CO, only 4,415 British thermal units 
are developed from each pound of carbon. A pound of 
carbon requires 1.33 lb. of oxygen in burning to CO, 
and 2.66 \h. in burning to CO^. If the air supply is in- 
sufficient, the first oxide only is formed, and hardly a 
third of the heat possible is obtained. In other words, 
more than two thirds of the possible heat units are lost 
at the top of the cupola. 

Even in the highest melting ratios which are obtained 
in practice the waste is excessive by comparison with the 
theoretical values. Even though the gases are burnt 
almost thoroughly there is much loss of heat in warming 



CUPOLAS, BLAST, AND LADLES 



55 



up 
of 



the inert nitrogen, in warming the blast, in radiation 
heat, and unavoidable heat losses in the iron and in 
the chimney. Actually a ratio of 10 to 1 
is very good; 8 to 1 is good; 6 or 7 to 1 
represents satisfactory practice. 

The rapid cupola. — The embodiment 
of this principle is illustrated by the 
Eapid cupola, by Thwaites Bros., Ltd., 
shown by Figs. 12 and 13. In this there 
are three zones of tuyeres enclosed by 
an air belt, and each zone of tuyeres can 
be opened and closed independently of 
the others by means of shut-off valves. 
The air belt, the zones of tuyeres, and 
] '11 £ the boshes or sloping sides, are, however, 



r 



^^> of older date than this particular ex- 

11 ample. Ireland's cupolas, much used a 

few years since, were very tall, and were 

provided with boshes or sloping sides 

similarly to blast furnaces, by which the 





Fio. 12.— The "Rapid" 
Cupola. 



Pra. 13. — Plan of Cupola 
THROUGH Tuyeres. 



weight of the charge was sustained. They, or at least 
the earlier ones, had two rows of tuyeres, but the upper 
row was abandoned in later structures. Voison's cupolas 



66 PRACTICAL IRON FOUNDING 

were made also with air belts and with two rows of 
tuyeres. Numbers of common cupolas, both in this 
country and in America, have the same arrangement. 
Cupolas have been made with shifting tuyeres, so that in 
the absence of an air belt the tuyere pipes can be 
moved to the zone above or below as required. 

The other features of the cupola are, a brick-lined 
receiver for the melted metal, by which means the heat 
is retained and oxidation prevented, while the blast pres- 
sure maintains its surface in agitation, conducing to 
proper mixture and homogeneity. The waste heat there- 
from is also utilized by passing up a ganister-lined pipe 
into the cupola, entering just above the air belt. The 
escape of the waste gases is regulated by a flap door at 
the side of the hooded top. 

The efficiency of this cupola ranks high, and it has 
given much satisfaction where it has been erected. In 
blows of ordinar}^ length it is capable of melting one ton 
of iron with from one, to one and a quarter hundred- 
weight of coke. Particulars of dimensions are given in 
the Appendix. 

The remarkable success of the air-belt design of 
cupola is due to the thoroughness with which theory has 
been translated into practice. It is based on the fact 
that there is no free oxj^gen above the tuyeres. Hence 
when the blast enters, its oxygen combines with the 
carbon in the fuel to form COo- This, in its ascent 
through the coke, unites with another atom of carbon, 
forming CO. This again demands oxygen for its con- 
version into COo, with development of intense heat of 
combustion. 

In other words, the conversion of as much as possible 
of the carbon in the fuel into COo within the melting 



CUPOLAS, BLAST, AND LADLES 



57 



zone is the object sought in order to develop all the 
heat units possible. The arrangement of supplementary 
tuyeres, of which there are usually half a dozen, sup- 
plies air in small volumes to the CO formed in the melt- 
ing zone. 

Tuyeres. — In arranging rows of tuyeres, diffusion and 
not concentration of blast must be accomplished, and to 
secure this the openings should not be arranged per- 
pendicularly, nor be very far apart vertically. If they 




Fia. 14. — Tuyeres of ISTewten Cupola. 



supply a uniform and sufficient quantity of air to the 
melting zone, which can be judged by the working of the 
cupola in economy of time and in hot metal, though not 
necessarily in fuel consumption, their real efficiency is 
demonstrated. 

The Newten cupola. Fig. 14, made by the Northern 
Engineering Works, of Detroit, Mich., has its lower tuyeres 
fitted with a differential device, the object of which is to 
send a portion of the blast right to the centre, while the 
larger volume is diffused more softly about the other 



58 



PRACTICAL IRON FOUNDING 



parts of the cupola. The tuyeres are of the enlarged 
form, giving nearly a continuous circle of blast; but near 
the centre of each, two plates are set to converge, en- 
closing the shape of a truncated cone through which the 
blast, being contracted, is forced to the centre of the 
cupola. The remainder of the blast is diffused more 
softly to right and left. 

Fig. 15 is a plan of the tuyere arrangements of the 
Whiting cupola, with a section through the wind-box. 




Fia. 15. — TuYETiics op WniTiNa Cupola. 



This shows in half plan the upper and the lower tuyeres, 
alternated or staggered in relation to each other. They 
are flared, being nearly double the width of opening at 
the inside than where they meet the belt. The position 
of the upper row is fixed, but the lower row may be 
adjusted to different heights. And when desired, the 
upper row may be closed with dampers if the amount of 
blast has to be lessened. 

Mdthuf ratio. — Various miscellaneous arrangements 
of relatively minor importance contribute to the economy 
or durability, or facilitate the working of the cupola. 



CUPOLAS, BLAST, AND LADLES 59 

The ultimate object is to melt as much metal as possible 
with the smallest expenditure of fuel, consistently, of 
course, with thorough melting. A certain quantity of 
metal, say a ton, is melted by so many hundredweights 
of coke, say two, three, or four. The first divided by the 
last gives the " melting ratio," a quantity around which 
foundry managers are in rivalry, and concerning which 
no statement can be made which shall be of more than 
very general application. 

The melting ratio must obviously be variable within 
wide limits, because it is under the control of so many 
conditions. Hence comparisons and statements can be 
of real value only if they are made under identical cir- 
cumstances. Sometimes the ratio is stated without in- 
cluding the amount of coke in the bed charge, which, if 
included in the case of a melting of short duration, 
might reduce the ratio by nearly or quite one half. In a 
prolonged melting, running down a large quantity of 
metal, the bed charge will form but an insignificant pro- 
portion to the whole. 

Again, in casting light work, the metal must neces- 
sarily be hotter, that is, more thoroughly melted, than 
for very massive work, and this requires a larger propor- 
tion of fuel; besides, a pure clean pig and scrap will re- 
quire less fuel to melt thoroughly than a lot of dirty 
inferior scrap, with much slag, will want. But even 
observing these differences, and including the bed 
charge, in all comparisons there is much difference in 
cupola performances, greatly to the disadvantage of the 
older types. 

Drop bottom. — The hinged drop bottom, though not 
in any way related to the efficiency of a cupola, is much 
to be preferred to the older solid bottom. The hinged 



60 PRACTICAL IRON FOUNDING 

door, on being released by a latch, allows all the con- 
tents to fall out at once. With a solid bottom they have 
to be raked out at the side, an operation which occupies 
ten or fifteen minutes, and is very hot work. It is neces- 
sary also to melt all the superfluous metal in order to 
run it out from a solid bottom, while it can be dis- 
charged from a drop bottom unmelted or partly melted, 
along with the partly burnt coke and slag. If water is 
thrown over it, the constituents can be separated and 
used again next day. 

Blast. — The proper pressure of blast is a matter of 
great importance. A soft blast will not melt the metal 
quickly nor thoroughly, and will cause wasteful ex- 
penditure of fuel. A sharp blast will blow away the fuel 
before perfect combustion ensues. Cupolas of large 
capacity have been made elliptical in plan instead of 
circular, to enable the blast to penetrate better to the 
interior. 

It is difficult to put in figures any rules for the blast 
pressure of cupolas, since it by no means follows that 
the pressure in a cupola is the same as that in the blast 
pipes ; it is really less — very much less — if the pipes are 
not selected of suitable size, and laid properly; and it is 
further very variable, depending on the condition in 
which the furnaceman keeps the cupola, the presence of 
slag, dirt, and partially choked tuyeres, and too close 
charging, so diminishing blast pressure. The pressure 
in a cupola varies within several ounces from the time 
of putting on the blast to the period of full melting. The 
differences are due to the increase of resistance of the 
molten iron and slag, preventing that ready escape of 
the air which occurs through interstices of the fuel and 
unmelted iron. A gauge supplies the means for reading 



CUPOLAS, BLAST, AND LADLES 61 

these variations of pressure. It is graduated to ounces, 
and reads to 2 lb. No cupola should be without one of 
these specially-constructed blast pressure gauges, in 
which the pressure or density is measured in inches of 
water. An inch of water gives a pressure of 0.5773 oz. 
per square inch. Blast pressure may range from 5 oz. or 
(3 oz. to 18 oz. Say we have, as an example, a pressure of 
12 oz., that would be equivalent to 6.9276 in. of water, 
or 0.88 in. of mercury, and this may be taken as a rough 
average approximation to ordinary cupola blast pressure ; 
or, putting it in round numbers, 7 in. or 8 in. of water, 
and 1 in. of mercury. The larger the furnace, the higher, 
of course, the pressure required. 

Fans and blowers. — For the production of blast, fans 
and blowers are employed, by which the air enters the 
cupola under pressure. There is no virtue in mere press- 
ure as such, but a certain rapidity of combustion is 
necessary in order to the efficient melting of metal. 
The pressure is not great, seldom more than 12 oz. per 
square inch, but at such a pressure an enormous volume 
of air passes through the tuyeres in the course of a min- 
ute. 30,000 to 40,000 cubic feet of air is necessary to 
melt a ton of iron, and from 20,000 to 30,000 cubic feet 
is necessary to consume 1 cwt. of coke. The volume of 
air is necessarily large, since, of the oxygen, much is lost 
through imperfect combustion, and the nitrogen is inert. 
The difference between a fan and a blower is, that the 
fan acts by inducing a current of air, the blower produces 
a positive pressure. The fan therefore has to revolve at 
a very high rate of speed, causing an attendant train of 
evils inseparable from high speeds; the blower need only 
revolve at a very moderate rate. The pressure and volume 
are under greater control with a blower than with a fan. 



62 



PRACTICAL IRON FOUNDING 



The common fan consists of an outer casing, cast in 
halves, and l)olted together. Within it revolve the 
hlades, or vanes, upon a spindle which runs in long 
hearings, and which is driven hy belt pulleys. The 





Figs. 16 and 17.— Types of Bloweks. 



revolution of the vanes produces a partial vacuum within 
the casing, into which air rushes from openings at the 
sides of the casing, gathering momentum, like a falling 
body, with increase of speed, and is forced out through 
the nozzle of the casing into the blast main. 

In the blower (Figs. 16 and 17), the air which enters 



CUPOLAS, BLAST, AND LADLES 63 

the casing (from below in the figures) is forced forward 
under constant pressure by the revolving pistons or 
impellers into the outlet above, which communicates 
with the blast main. These impellers are of cast iron, 
shaped to templet, and fit so accurately into each other, 
and to the bored casing, that the thickness of a sheet of 
paper alone preserves them from actual contact. The 
narrow, almost pointed ends serve to sweep out any 
deposit of dirt or grit which may enter within the casing. 
Being lubricated with a very thin coating of red oxide 
paint, they run, though practically air-tight, with the 
very minimum of friction. Two examples of Koots' 
blowers are shown by Fig. 18, Plate I, and Fig. 19, 
Plate II, the first being geared direct to an electric motor, 
the second driven by the special type of engine which is 
used for these, with two connecting rods. Ordinary high- 
speed enclosed type engines are also employed for this 
function, with a heavy flywheel on the shaft, and con- 
nection to the second shaft by the usual gears. These 
are by Thwaites Bros., Ltd., of Bradford, Yorkshire. A 
table of the performances and other particulars of Boots' 
blowers is given in the Appendix. 

In Baker's blower there are three revolvers or drums, 
each of circular section. Two of these are slotted through- 
out their entire length in order to allow the pair of 
radial wings in the upper drum which propels the air to 
clear inside them. The lower drums are so arranged 
that contact is never broken between one or other of 
them and the upper drum. The upper drum is furnished 
with two radial arms which alternately sweep through 
the hollow portions of the two drums placed beneath it 
In this case also the casing is bored out truly to prevent 
escape of air and to ensure smooth working. 



64 PRACTICAL lEON FOUNDING 

Controversy respecting the relative merits of fans and 
blowers is perennial. Each has its advocates, but an un- 
biassed mind will admit that between the best of each 
there is little if anything to choose. The points in favour 
of each are these. 

With the blower, practically the same volume of air 
which is drawn in must be forced out, for a well made 
machine should have no perceptible leakage. Hence the 
volume of air can be controlled exactly by varying the 
number of revolutions of the blower, an increase in which 
increases the melting capacity of a cupola. The volume 
of air supplied being uniform under similar conditions 
the pressure increases with resistance offered, so that a 
blower will force air through slag obstructions, or through 
charges of increasing density. So that pressure may rise 
from 8 oz. to 10 oz. in the course of a blow. This is all 
in favour of the blower. Moreover, very minute fluctua- 
tions occur in pressure during each revolution, occurring 
each time the arm of an impeller discharges air. This is 
also claimed as of value in regular melting. 

The fan acts by imparting momentum to the air and 
not by displacing a precise volume equal to the cubic 
capacity of the blower. The term centrifugal denotes that 
the air is delivered by centrifugal force at the circum- 
ference. The rotation produces a partial vacuum about 
the centre, to occupy which air enters at the openings in 
the sides. Pressure is increased with increase in the 
rapidity of the revolutions, and in the ratio of the square 
of the speed. The speed of a fan cannot be increased 
beyond the proper speed for which it is rated without 
absorbing additional power in the ratio of the cube of the 
number of revolutions. So that a fan will, under these 
circumstances, be a wasteful machine. Actually fans 



PLATE II 




See 2}. 63 [Facing p. 64 

Fig. 19. — Roots' Blower, driven by Self-contained 
Steam Engine 



CUPOLAS, BLAST, AND LADLES 65 

should be selected of capacities large enough for their 
work, and for this the tables of manufacturers may be 
accepted as a working basis. And further, the pipe 
arrangements must be free, large, short in length, and 
without any quick bends, if the fan pressure is to be 
maintained at the cupola. The fan is not so well able 
to force air through dense charges of slag as the blower 
is. On the other hand it produces a softer blast. It is 
desirable with fans to have a blast gate in the main pipe 
for regulating the supply as the demands made upon it 
vary. The elasticity or tlexibility of the fan, its self- 
adjusting capacity, is in its favour in the opinion of many 
foundrymen. But unless a fan is selected fully large 
enough for its work and run at suitable speeds, it will 
prove very inefficient. In its favour is that of costing 
less than the blower, requiring less solid foundations, 
and being less expensive for repairs. 

The attempt has been made to employ a jet of steam 
to induce the blast current. This was the peculiarity of 
Woodward's cupola. 

In the Herbertz cupola also the blast is induced by an 
exhausting jet of steam. The jet operates in a flue near 
the charging door, and the blast enters through an annu- 
lar opening immediately above the hearth. The width 
of this opening is capable of adjustment by means of 
screws for the production of a cutting or of a soft blast. 

Ladles. — For the pouring of metal into moulds, ladles 
of various kinds are employed. The ordinary forms are 
shown in the accompanying illustrations. In the group of 
Fig. 20, Plate III, the smallest, the second from the top, 
is a hand ladle holding a half hundredweight only, used 
for very light casts and supplying feeder heads with hot 
metal. Above it is seen the double handled shank ladle, 

F 



66 



PRACTICAL IRON FOUNDING 



made in capacities ranging from one to about four hun- 
dredweights: two, three, or four men carry these ladles, 
according to the weight. Thus there may be one, or two 
men at the cross handle; and one, or two at the straight 
shank. When made for two, the end of the shank is 




Fig. 21. — Double-geared Ladle. 



turned down, and is supported on a cross bar, each end of 
which is held by a labourer. The third do^vn in the group 
is a heavier, or crane ladle; it may range from ten hun- 
dredweights to a ton in capacity. It is slung in the crane 
hook; the catch seen on the right prevents the ladle from 
becoming accidentally up-tipped, and, when thrown back, 
a man standing at the cross handle turns the metal into 



CUPOLAS, BLAST, AND LADLES 



67 



the mould. The heaviest ladles are of the type shown 
below. These are r/eared ladles, which may range from 
one to twelve tons in capacity. The geared ladle was the 




Fig. 22. — Double-geared Ladle. 

invention of Mr. Nasmyth, and a graphic illus- 
tration of the contrast between it and the old ungeared 
form is given in his admirable autobiography. The ladle 
in the Fig. is double geared, having mitre wheels in 



68 



PB ACTIO AL IRON FOUNDING 



addition to the worm gear. Many ladles have the latter 
only. A weight of several tons is tipped easily and 
steadily into the mould by means of the geared ladles. 




Fig. 26. — Gtogdwin and How's Patent Ladle. 



Figs. 21 and 22 show the construction of a double- 
geared ladle by Charles McNeil, of Glasgow, of 25 cwt. 
capacity. The worm gear for tij^ping is turned by the 
application of the handle either directly on the square 



CUPOLAS, BLAST, AND LADLES 



69 



on the worm shaft, or if more convenient at right angles 
on the square of the mitre gear shaft. Fig. 23, Plate IV, 
represents a worm-geared ladle of 12 tons capacity, by 




Fig. 27. — Goodwin and How's Patent Ladle. 



Messrs. Thwaites Bros., Ltd., with riveted body, and 
Fig. 24 is a 10 cwt. ungeared ladle mounted on a four- 
wheel bogie. A heavier class of ladle — 5 tons capacity — 
Fig. 25, Plate lY, is provided with a lifting bar so that 
it may be lifted on and off by the crane. The eight- 



70 PRACTICAL IRON FOUNDING 

wheel bogie carriage has ball-bearing swivels, and the 
wheels are flanged to run on a track. These ladles are, 
except the smallest, which are of cast iron, made of steel 
plate riveted together. The McNeil ladles are of pressed 
steel. 

Ladles are daubed every morning before casting with 
fire-clay, or loamy sand, and blackwashed. This lining 
is dried, in the case of the smaller ladles, over a coke 
fire, in the larger ones by lighting a fire of w-ood within 
them. After casting, the skulls are chipped out with a 
hand hammer. 

Skimmimg. — When metal is poured from a ladle, a boy 
holds a rectangular bar of iron across the mouth, to bay 
back the scoriae which floats on the surface, so prevent- 
ing it from entering the mould, to the detriment of the 
casting. The method is necessarily an unsatisfactory one, 
but few attempts have been made to remedy it. Two 
forms of ladles have been patented, having a bridge or 
bar dividing the spout from the body; the Craven and 
Chapman is one; the other, Goodwin and How's, is 
illustrated in Figs. 26 and 27. From these it is seen 
that the body of the ladle is pear-shaped, the shell being 
extended on one side to form an external spout, which is 
separated from the body by a skimmer or dividing plate, 
projecting above the top of the shell, and descending to 
the required distance from the bottom. It is held in 
position by eyes, pins, and cotters at the top, and 
by finger plates at the bottom. The skimmer plate is 
readily removable for repairs. The principle of taking 
the metal from the bottom is an excellent one, and has 
long been adopted in the steel-casting ladles, fitted with 
a goose neck and plug. 



CHAPTEE V 

THE SHOPS, AND THEIR EQUIPMENT 

Situation. — When designing an iron foundry, everything 
must depend upon situation and upon the space avail- 
able; but there are certain main considerations which 
may be briefly stated. In the first place, the soil ought 
to be dry. One of the greatest difficulties in some low- 
lying districts is to get a sufficiently dry site. This, 
which is a matter of slight consequence in the building of 
a machine shop or boiler shop, is of serious import when 
a foundry is concerned. In spongy ground, and ground 
liable to floods, moulds sunk in the floor are always 
liable to damage. In such cases new ground should be 
made up of a height sufficient to be above the reach of 
water, and especial care be taken in so lining the casting 
pits as to render them impervious to moisture. 

The building also ought to be lofty and well ventilated, 
to carry off the sulphurous fumes and smoke present in 
all foundries. There should be plenty of light. Ven- 
tilation and light are as essential in a foundry as in a 
machine shop. Both should be mainly provided in the 
roof. A foundry cannot be too well lighted. So much of 
the work is, in itself, involved in shadow, as in deep lifts, 
setting of cores, etc., that even in the best-lighted shop 
the use of lamps in the daytime is frequently necessary. 
If the roof is well lighted, little side light is required. 
Still, the more the better, and, whenever practicable, side 

71 



72 FB ACTIO AL IRON FOUNDING 

windows should be included. Further, the building should 
be of the same section throughout, in order that a tra- 
velling crane may run from end to end without hind- 
rance. Again, if a large area is required, it is better to 
obtain that by giving increase in width rather than ex- 
cessive increase in length, and this not by unduly widen- 
ing a single sj^an, but by doubling or trebling the spans, 
either making two of equal breadth, or flanking a main 
span with one or with two narrower side ones, according 
to circumstances. This arrangement is economical in 
respect of the carrying of metal and materials, flasks, 
and tackle ; and it permits also of better overlooking and 
supervision. In any span there should always be clear 
floor room throughout, and this is of prime importance. 
To have cranes stuck about in the middle of a shop is a 
bad arrangement, because they occupy valuable room, 
and make the transit of metal awkward. 

But these general conditions often have to be modified 
by circumstances, because the planning of any workshop 
may be hampered by the ground plan of the premises. 
The proximity of certain departments is desirable, and 
parallel bays are not always practicable. 

Enlargement. — The possibility of future enlargement 
must be considered in laying out a new foundry. And 
extension can only be effected on the ground. No shops 
can be built over, because the heat and sulphurous 
fumes forbid it. Future extension must be provided for, 
longitudinally, or laterally, by increasing the length of a 
bay, or by adding a new bay or bays at the sides of the 
primitive building. A beginning can be made with a 
square building, equipped with a central crane, and one 
or two wall cranes. That is not a very good plan, but 
many small shops are constructed thus. In a future 



THE SHOPS, AND THEIR EQUIPMENT 73 

extension the shop would be made oblong, and the crane 
would remain to serve the heavy loam work, while the 
added length might be served with a traveller and light 
wall cranes. When starting a block of buildings, the 
proximity of stores, etc., must be borne in mind to save 
unnecessary handling of materials. 

Cupolas. — Two cupolas are necessary in any foundry. 
The smaller will be of about 2 ft. 6 in. diameter, the 
larger will range up to 4, 5, 6, or 7 ft., according to the 
weight of work done. In a large foundry two cupolas or 
more of the largest capacity may be required for the 
day's casts. Besides these, it is often convenient to have 
a small one of from 16 to 18, or 24 in. diameter, having 
a capacity of from 10 to 30 cwt., for the purpose of mak- 
ing tests of mixtures, casting test bars, making a special 
light cast, etc. 

Generally it is convenient to locate the cupolas to- 
gether for convenience of charging and blowing. Inside 
the foundry it would often be more convenient for the 
tapping of metal to locate cupolas apart from one another. 
In the case of special departments of work, such arrange- 
ments must sometimes be made. The general rule, how- 
ever, is to set cupolas together, as nearly centrally as 
possible, in order to lessen the distance of carriage of the 
metal, and the loss of blast pressure. In many foundries 
the practice is to locate the cupolas without the building, 
passing the tapping shoot through the wall into the in- 
terior. In others the lower portions are within the build- 
ing, and the upper parts pass out through the roof. The 
latter has the advantage over the former, that the furnace- 
men are protected from weather, and that the foreman 
can observe the melting without going outside. But if 
the cupolas are placed without, a door at the side permits 



74 PRACTICAL IRON FOUNDING 

ready egress. Hydraulic hoists, or geared pulley-driven 
hoists, will be located at the cupola stagings for lifting 
iron and coke from below. 

Large ladles of metal are carried away with the tra- 
veller, or with a ^valking crane, or swung round in a jib 
crane to moulds within its radius. Light casting is some- 
times done from a tipping ladle on a bogle running on 
rails down the shop. The moulds are either poured 
directly from the ladle, or it is used to supply the smaller 
hand ladles which fill the moulds in its passage down the 
shop. Shank ladles, containing from 56 lb. to 4 cwt. are 
generally carried by hand. 

Core Ovens. — The dimensions of core ovens and drying 
stoves depend upon the nature of the work done in a 
given foundr}^ The largest stoves run to 20 ft. or 24 ft. 
long, by from 10 ft. to 12 ft. wdde. Height also will de- 
pend on the class of ^York, ranging from 6 ft. to 10 ft. 
Carriages will occupy from 1 ft. to 2 ft. of this height. 
In cases where work exceeds 6 ft. or 8 ft. in height, it is 
usual to effect a division in the mould, parting it into 
tw^o, which are placed separately on the carriage. The 
largest stoves should be adjacent to the area where loam 
work is done. The smallest stoves are better located else- 
where, adjacent to the small core-making departments, to 
be used for the drying of cores, or of small moulds. The 
stoves, except those for ver}^ small cores, are always 
built outside the foundry, the doors being flush with the 
interior of the foundry walls. Stoves are fired with coke 
from the outside — that is, from the end farthest from the 
doors. In some cases, however, the grate is built inside 
in the centre of the floor. The neatest way of firing is by 
producer gas, or the waste gas from furnaces. The car- 
riages containing the cores are made in cast iron, framed 



THE SHOPS, AND THEIR EQUIPMENT 75 

together, and covered with loose plates. They are run in 
on rails which lead from the shop into the stove. Pro- 
vision is made in some foundries for drying large moulds 
in the foundry pits. The latter are of large area, and are 
heated by gas, being covered over with iron plates during 
the drying process. 

Tracks. — Narrow bogie tracks might advantageously 
be used to a greater extent than they are in English 
foundries. The objection to their use is that they occupy 
some floor space that might be required, and that the 
ladles are apt to spill some of their contents if the track 
becomes temporarily obstructed. In reference to the 
first, a fairly clear way down the centre of the shop must 
of necessity be kept for the transit of materials, and of 
metal if carried in hand ladles. In reference to the 
second, mishaps need not occur if a labourer is made re- 
sponsible for keeping the ways clear. Also, similar mis- 
haps occur with hand-carried ladles. Further, too, other 
materials beside metal are carried on the tracks, and 
tackle also. The advantages are: Facility in transit, 
avoiding the changing of heavy ladles from one crane to 
another and saving in labour, one man being able to 
push along a load which would require three or four men 
to carry in shank ladles and by hand. In the light 
foundry more especially, the tracks are of value, since a 
ladle carrying 5 cwt., 8 cwt., or 10 cwt. of metal can be run 
over from the cupola and made to feed a dozen or twenty 
small moulds ranged along its track. For small moulds 
not in the line of track, the light 561b. hand ladles can 
he dipped into the larger ladle close by, instead of run- 
ning across to the cupola with them. Probably most of 
our readers know that one of the largest foundries in 
England — that at Crewe — has tiny locomotives running 



7Q PRACTICAL IRON FOUNDING 

on its tracks. Not only for pouring, but also for running 
along flasks, sand boxes, and other material, is the track 
serviceable, saving hand- carrying for light loads and fre- 
quent waiting for the traveller to be at liberty for heavy 
ones. 

With rare exceptions the tracks are always narrow, 
seldom exceeding about 18 inches gauge. The rails are 
either cast on plates, or they are fitted on cross-sleepers. 
Casting-on is a convenient device for several reasons. The 
rails may stand above the plates, or preferably be flush, 
flanked by recesses for the wheel flanges. Such tracks 
are arranged to connect with the yard tracks and thence 
with the other shops of the works. 

The narrow-gauge tracks may run uniformly through- 
out the works, or not go beyond the shop doors, as when 
wide-gauge standard tracks serve the yard. These then 
come up to the foundry doors so that articles can be 
loaded and unloaded from standard to narrow and vice 
versa. Suitable trolleys are built for foundry service, being 
plain, or with sides to suit different classes of castings. 

Casting pits. — These are either oblong, circular, or 
polygonal in form, and their purpose is twofold. The 
oblong pits are comparatively shallow, but of large area, 
and are used for moulding work which has to be dried, 
but which is so massive that it could not be dried in the 
ordinary core stove, or, if dried, could not be moved from 
the floor to the pit. Hence it is rammed, dried, and cast 
in situ. The circular and polygonal pits are usually very 
much deeper than the oblong pits, and the work may or 
may not be moulded and dried in them, but is as a rule 
moulded on the floor, dried in the drying stove, and only 
lowered into the pit finally for casting. The oblong pits 
being shallow, are generally lined only with brickwork, 



THE SHOPS, AND THEIB EQUIPMENT 77 

except in damp and low-lying situations where water 
could gain access, when they are of iron. They are 
covered over with movable plates of cast iron to confine 
the heat while drying, and are dried with gas. The deep 
pits, on the contrary, have no covering, being simply 
receptacles for finished moulds; but, being deep, they 
are often liable to the entrance of water, and are 
therefore lined throughout with iron plates, consisting 
either of boiler plates riveted together in the form of a 




Fig. 28. — Foundry Pit. 



cylinder, or of cast-iron plates bolted together with flanges 
like tank plates (Fig. 28). The bottom is similarly formed 
of iron plates. 

When bricking-up work in the pit it is often necessary 
to erect staging at intervals for the men to stand upon 
while working; ladders, also, are sometimes placed in the 
pit, and planks laid across the rungs, but it is better to 
make provision when building the pit for such staging. 
When boiler plate is used, rings of angle iron can be 
riveted around at various heights for this special pur- 



78 PRACTICAL IRON FOUNDING 

pose; ribs maybe cast on cast-iron plates when such are 
employed, or the pit itself may be constructed with rings 
or plates, the diameter of w^hich increases as the series 
ascends, so as to form ledges at intervals all the w^ay up. 

When it is required to diminish the size of a large pit 
for a temporary purpose in order to put a small job in, 
loose rings are lowered down and the work rammed up 
inside them as at A (Fig. 28). Large casting pits will 
range from 30 ft. to 70 ft. in length, by from 18 ft. to 22 ft. 
in width; small ones from 8 ft. to 12 ft. or 14 ft. in 
diameter. 

Offices, etc. — The foreman's office should overlook the 
entire shop, and be roomy enough to permit of the mak- 
ing of tests, and for the clerical work of the foundry. 

The pattern bench never need be large. Patterns ought 
not to lie about long in the foundry. The foundry bench 
is not a store, but simply a receptacle for jobs wanted, 
and as soon as they are done with they should be cleared 
away from the shelving and a fresh supply of patterns 
sent in. 

Narrow shelving — one or two rows — is arranged round 
the walls for the reception of small patterns after mould- 
ing, and a few moulders' small requisites — lamps, nails, 
etc. As soon as the castings are turned out and passed, 
the patterns must be removed, otherwise loose pieces will 
be lost and parts damaged. 

Stores for the foundry, and the various machinery for 
the same, should be located close to the building, in such 
a manner that time will not be wasted in obtaining any- 
thing required Coke, sand, iron will be kept in sheds, 
and the machines for grinding, mixing, and breaking 
will be adjacent, and rails, trucks, and hoists will convey 
the materials whenever required. The sand and other 



THE SHOPS, AND THEIR EQUIPMENT 79 

sheds may open into the foundry, or may be located out- 
side. There is so much dust, dirt and Utter attending 
these, that it seems better to have them to open outside 
the foundry than into it, adjacent to the work of 
moulding. 

The fettling shop must always be parted from the 
foundry itself. The reason is that the chips, the fins, etc., 
that are chipped off the castings must not be permitted 
to mix with the foundry sand. In the fettling shop there 
will be a bench with vices, small emery wheels for grind- 
ing off fins, scabs, etc., and a tumbler or rattle barrel for 
cleaning off sand and smoothing surfaces. 

The location of the pig and scrap iron will depend on 
local conditions. It is not necessary that the iron shall 
be close to the cupolas. It may be elsewhere, provided a 
track is brought from the iron stores to the cupola. 

Departments. — If there are specialities in firms, as 
there are in most cases nowadays, each should be con- 
fined to a separate department. This is simply an exten- 
sion of the principle of keeping in a general shop certain 
men on certain classes of jobs. Thus, wheel moulding, 
cylinder moulding, light green-sand, heavy green-sand, 
etc., will be done by men who will be kept as far as prac- 
ticable each on his class of work. To keep separate 
classes of work in separate departments follows naturally 
as the volume of trade increases. Sometimes these de- 
partments will be located in separate buildings, or in 
different portions of a single building. It is always de- 
sirable to make a distinction between light and heavy 
work, because that permits of a suitable arrangement 
of hoisting tackle, flasks, proportion of unskilled labour 
required, and so on. Loam work must always be kei^t 
distinct from everything else, because of the special 



80 PB ACTIO AL IRON FOUNDING 

tackle required, the ground area occupied, the proximity 
of drying stoves and casting pits, and heavy hoisting 
tackle, and because of the dust created in filing and 
finishing moulds. Plate moulding, with or without the 
aid of machines, requires its own special area and tackle. 
So does railway-chair work, ploughshare work, malle- 
able cast iron work, etc. Engine cylinders, liners, and 
slide valves, also, when made in large numbers, should 
have a separate shop, and a cupola for the melting of 
special metal. Brass work is always relegated to a dis- 
tinct shop. 

Everything which can be kept under cover should be 
so kept. A considerable weight of metal is lost in 
rust every year when tackle is left in the open. Standard 
grids, core bars, and the smaller flasks can all be kept 
in sheds without encroaching on the foundry area. 

Foundry doors must be made amply large enough to 
pass the largest patterns or castings ever likely to be 
constructed. The main doors should not, as a rule, be 
less than 12 to 14 ft. wide, and from 10 to 12 ft. high. 
They are made of sheet iron to slide sideways, or ver- 
tically; in the latter case being counterweighted. Hinged 
doors should never be used. Smaller doors will be placed 
at various parts to suit various requirements. 

The average foundry is almost invariably the most 
badly-equipped of any engineer's department in regard 
to labour-saving appliances. There are foundries now, 
considered good, in which there is no machinery and no 
labour-saving appliances worth mentioning — in which 
work is carried on by precisely the same methods which 
were in operation a quarter of a century ago, and where 
everything is still done by dint of pure physical effort; 
moulds made, metal carried, castings cleaned, etc., with- 



PLATE III 





Seep.^^ [Facing I). SU 

Fig. 20.— Ladles, by Thwaites Bros., Ltd. 



THE SHOPS, AND THEIB EQUIPMENT 81 

out the most obvious economies which have long been 
practised in the leading firms. If a fractional part of 
the money which is lavished in the other departments 
to save unskilled labour were spent in the foundry to 
lessen the cost of skilled labour there, the results would 
in time prove eminently satisfactory. The reason why 
this condition of things exists is that the class of work 
done in pattern shop and foundry is of a different char- 
acter from that carried on in the boiler and machine 
shop, in this respect — that the work is not usually so re- 
petitive there as in these. 

There is some machinery which is indispensable in 
any foundry. There is much, also, of a more or less 
special character, the cost of which is either too heavy 
for small foundries, or else it is machinery which is 
adapted only for certain classes of work. 

Indispensable machines are the coal mill and loam 
mill. Those which are seldom used in small foundries, 
but which are found in most large ones, are sand- sifters, 
emery wheels, rattle barrels, testing machines, and ma- 
chines for breaking pig iron and coke. Machines of a 
special character used in special departments of large 
foundries doing general work, and in any shops doing 
special work, are the plate-moulding and the wheel- 
moulding machines. Articles which come under the 
head of appliances, and which are essential everywhere, 
are wheel-barrows, ladles, shovels, riddles, sieves, scratch 
brushes, core trestles, iron core boxes, flasks, etc. 

Cranes. — These are of three kinds — post cranes, which 
slew completely round; wall cranes, which slew within 
a more limited range, generally 180 degrees; and over- 
head travelling cranes, the range of travel of which covers 
the whole of the floor area of the shop. The post cranes 

G 



82 PRACTICAL IBON FOUNDING 

are very useful when the shop is of moderate size and of 
quadrangular form. The framework, triangular in out- 
line, may be constructed either of steel or of wood. The 
post is pivoted in a toe step in the ground, and in a 
socket attached to cross timbers in the roof trusses. Pro- 
vision is made for lifting by single and double gear, and for 
racking inwards and outwards; the latter being essential 
for the precise adjustment of the ladles in relation to 
the moulds, which are arranged on the floor. The power 
of such cranes may range from three to fifteen tons. 

The wall cranes are necessarily of light construction, 
ranging between powers of one and two tons only. 
The framework consists of horizontal jib, and ties only, 
made in steel. The hoisting gears are attached to a 
bracket which is bolted to the w^all, independently of 
the main framework. A racking carriage travels on the 
horizontal jib, and is worked by means of an endless rope 
depending from a spider wdieel above. These are used 
for turning over and lifting the light moulds, and 
smaller ladles, and if ranged in series, each within range 
of the radius of its fellow, ladles can be passed down 
the shop rapidly, being transferred from crane to crane 
with changing hooks. 

But the overhead traveller has the best arrangement 
for all except the very small shops. The traveller moves 
along the gantry beams which are supported on the 
stone abutments of the walls, and the crab has a trans- 
verse motion across the traveller beams. The whole 
area of the floor can thus be covered at will. Travellers 
when of small size are worked by hand from below 
with endless ropes, many of those of larger size by a man 
stationed on the crab above. Travellers of all sizes are 
now actuated electrically. 



THE SHOPS, AND THEIR EQUIPMENT 83 

These will be differently arranged according to cir- 
cumstances. There should be at least one overhead 
traveller in each bay, operated by hand or by electricity. 
It is well to have two travellers — one light and one 
heavy — in long shops where a lot of handling of flasks 
has to be done. In addition there must be several hand, 
electric, or hydraulic cranes. Columns can be utilized 
for the attachment of cranes which swing in a complete 
circle to serve adjacent bays. It is necessary to have 
jib cranes, as well as a traveller, in a foundry bay, be- 
cause a single traveller cannot serve all the requirements 
of a foundry. They should not be in the middle of the 
shop, because they would be in the way. If a crane is 
placed in the centre of a bay it must be located at one 
end, in order not to interfere with the work of the 
traveller, or with the clear floor area necessary. At one 
end it may serve for the heavy loam work, or heavy 
green-sand work. Any jib crane which is adjacent to 
another crane should cover its radius, for the conveni- 
ence of changing flasks or ladles from one to another. 
All jib cranes must have racking movement to cover any 
work lying between the post and the maximum radius, 
and therefore they must have horizontal jibs. Walking 
cranes are sometimes used in foundries, as in machine 
shops and turneries. They cover the whole area without 
remaining a permanent block. But they are not so well 
adapted for heavy work as the travellers. 

Converted and single-motor travellers are undesirable. 
Each motion, — hoisting, longitudinal, and cross traverse 
should have its own motor, and a heavy traveller should 
have in addition an auxiliary hoist for light loads. 

Poiver, — In making selection of power for a foundry 
at the present time, broader views have to be taken than 



84 PRACTICAL IRON FOUNDING 

formerly. Not only have new applications of power 
agencies come into the field, hut the foundry itself has 
heen radically reorganized and remodelled. Many recent 
foundries are machine-moulding shops ; others have gone 
far in that direction. Human muscle — a hig asset in the 
older shops — is of less account now than it was at one 
time. Mechanical aids to lift and carry are uhiquitous. 
As foundries have heen re-designed, so also have power 
agencies hecome readapted. 

One fact should seem so ohvious as hardly to need 
stating, namely, that no single answer can he given to 
the question that would be of universal application. 
There is, for example, very little in common between a 
foundry doing all light work and another handling only 
heavy work. A foundry which deals with both classes 
stands in a different category from one manufacturing 
specialities, and so on. Each shop must be considered 
as an entity apart from any other. The following re- 
marks are intended to embrace the principal conditions 
which exist in foundries. 

The natural course to adopt in approaching the power 
question is to take first a brief survey of the services for 
which power is demanded or is desirable. These are 
hoisting and carrying power for the cupola, machinery 
for the preparation of materials, machinery for making 
moulds, and that for cleaning castings. 

Hoisting and carrying machinery. — These are included 
under one heading because they are intimately related, 
though carrying on tracks is independent of hoisting. 
But all cranes carry as well as lift, and one of the prin- 
cipal differences in them lies in their range of action, 
which is least in a swinging crane, and greatest in over- 
head travelling cranes, and hoists on overhead tracks. 



THE SHOPS, AND THEIR EQUIPMENT 85 

The power agencies include hand, steam, electricity, 
compressed air, and pressure water. 

Hand power. — Hand power cannot be left out of ac- 
count, because small foundries in country places depend 
mainly upon it. Such foundries are not able to afford 
an expensive power plant of any kind. The demands for 
crane service are too limited, too intermittent, to justify 
the capital outlay involved. For these the hand-operated 
overhead travelling crane offers a cheap source of power. 
It is made to be operated by a labourer on the crab, or 
from the floor by a dependent chain. A swinging jib 
crane, or two, judiciously located against walls, to cover 
certain areas where such help is most needed, may well 
supplement the overhead traveller. Such cranes must 
have horizontal jibs along which the jenny can be 
racked. Neither cranes with fixed jibs, nor derrick cranes 
with luffing jibs, are suitable for foundry service. In 
shops equipped with hand cranes the power which can 
be most economically installed is a steam-engine for 
driving the blower, the sand and coke mills, and tum- 
blers. This is the simplest and cheapest, the driving 
then being done by means of belts. This machinery, 
small in amount, but indispensable, can be located 
adjacent to the blower and cupola, preferably in a shed 
outside the foundry wall. 

Steam power. — Steam power may be ruled out entirely 
now in all ordinary foundries of medium and large di- 
mensions for new installations of hoisting machines. 
Electricity has almost wholly superseded it, and where 
this is installed it serves also for the driving of the 
blower and the grinding mills. Overhead steam tra- 
vellers and rope -driven ones were always somewhat 
of a nuisance, which accounts for the rapidity with 



86 PRACTICAL IRON FOUNDING 

which they disappeared as methods of electric driving 
improved. 

Electric power. — Electricitj^ is the agent which in 
foundries, as in other shops, is the most flexible and 
mobile form of power. The work of the foundry is more 
intermittent than that of the machine shop, and elec- 
tricity is eminently adaptable to such conditions. At 
casting time, and when castings are being removed from 
their moulds, the cranes are fully occupied. During the 
middle of the day their service is intermittent. When 
electric cranes are not running they are using no power, 
and when in operation they absorb only the amount 
which corresponds with the demands made upon them. 
Also, nearly all cranes now built have separate motors 
for each motion, and for heavy and light loads, rated 
suitably for the different speeds and loads, thus not only 
economizing power, but getting the most suitable speeds 
for every separate motion. 

The distribution of electric power from the power 
house entails the employment of a considerable number 
of motors distributed where required. But against their 
cost is to be set the fact that they are eminently adapted 
to foundry service where the cranes and machinery are 
scattered and used very intermittently, and they compare 
in this respect most favourably with any other method of 
power distribution. In a large foundry the average load 
on the motor is low, because the intermittent periods 
when no power is being used are frequent and long in 
the case of almost all machines. 

In a large foundry the facilities for transmission which 
the electric cables afford contrast most favourably with 
those of steam pipes, square shafts, or cotton ropes. 
One power house will supply all the current required 



THE SHOPS, AND THEIR EQUIPMENT 87 

for cranes, blowers, and machinery used in the foundry. 
Cables supply the cranes with current, which is switched 
on to motors on the cranes only when required for 
service. 

Blowers and various machines are belted preferably 
from short lengths of motor-driven shafting suitably dis- 
posed. Blowers are designed to suit every kind of drive. 
A motor is directly coupled to the blower shaft, or it is 
driven through one set of reduction gear, or a belt drive 
is taken from a countershaft above, or from a counter- 
shaft on the same bedplate as the blower, with provision 
for belt tightening. Or a steam-engine often drives the 
blower direct, being mounted on the same bedplate. 

These variations are adaptable to different local con- 
ditions, and the reason why the blower is thus favoured 
lies in the desirability of locating it in a room by itself, 
away from other machines, in order to prevent access of 
dust to the interior. The sand and coal-grinding mills 
are better belted from a motor-driven countershaft. The 
machines in the fettling shop are similarly operated. 

Compressed air. — This is a source of power which is 
almost indispensable in any foundry of ordinary dimen- 
sions, apart from its utilities in operating light hoisting 
machinery running on overhead tracks, and in some 
types of moulding machines. The utilities of pneumatic 
rammers, and of pipes for blowing loose sand away from 
pattern faces and out of moulds, are of much value, as 
also is the sand blast for fettling castings. These alone 
are sufficient to justify the pneumatic installation. 
Whether to extend the system to the operation of hoists 
and of moulding machines must be answered differently 
in different foundries. 

The light pneumatic hoists on overhead tracks, covering 



88 PRACTICAL IRON FOUNDING 

the entire floor area, are a great help in many foundries. 
But since electric power has been installed so generally, 
electric hoists have often been preferred. The electric 
cable is to be preferred to air-supply pipes with their 
risks of leakages. The elasticity of the air lift, though 
not very marked in the best modern hoists, is still ob- 
jectionable when withdrawing patterns, and when turn- 
ing over boxes of moulds. 

On the other hand, the cost of pneumatic hoists is 
less than that of electric ones, which have to include 
one or two motors, besides gears. Electric hoists are, 
however, better suited to the heavier loads than pneu- 
matic types. Compressed air is used in many power- 
rammed machines, and its use is increasing. But many 
firms prefer, or are committed to, hand machines. Then 
the air hose should be an adjunct for blowing surplus 
sand out of the moulds. 

Hydraulic power. — Pressure water is used very largely 
in German foundries. The reason of this, aj^parently, 
is that in the German shops heavy machine moulding 
has developed more extensively than in any other coun- 
try, and for this, hydraulic pressure has no rival. But 
apart from this service, pressure water is now rarely 
installed in foundries; that is, it would seldom be used 
for cranes, unless already in use or contemplated for 
heavy moulding machines. 

Formerly, in a fair number of foundries, hydraulic jib 
cranes were employed, and they have the advantage of 
being easily and minutely controlled. But there are 
several disadvantages incidental to the pipe connections 
and valves, and the liquid used, and the system is not 
adaptable to the other services of the foundry — the over- 
head travellers and the blowers and machines. The 



THE SHOPS, AND THEIR EQVIFMENT 89 

combination of steam with water, the steam-hydrauHc 
system, has been employed rather extensively; but the 
disadvantages of the transmission apply to this as to 
the hydraulic, comparing unfavourably with the electric 
conductor. 

Miscellaneous machines. — Cupola hoists are operated 
by whatever source of power happens to be installed. 
Direct hydraulic operation is the best if pressure water 
is available. But failing that, either steam or electricity 
are quite suitable. The latter is now predominant. 
Some cupolas have bucket elevation, and transportation 
bucket gantries. 

Trolleys on tracks for transportation of materials, 
boxes, and castings are simply pulled or pushed by 
hand. In rare instances light locomotives are employed 
in extensive foundries. 

Machinery for the preparation of materials includes 
pig breakers, sand grinders, sand sifters and mixers, coal 
mills, and loam mills. The best arrangement for these is 
that of short lengths of countershaft, motor-driven, with 
fast and loose pulleys to throw any machine into or out 
of action. 

Machinery for making moulds includes chiefly the 
various moulding machines, and then all subsidiary con- 
veying systems, which, however, are used only in shops 
where the output is large, and where power is available. 
The employment of a large installation of moulding ma- 
chines need not, and often does not, involve a power 
plant, for the majority in use are still hand-operated. 
Patterns on machines of large dimensions can be dealt 
with thus, so nicely are heavy parts counterbalanced, 
and combinations of levers devised. Hand ramming and 
pressing is also more common than power ramming. 



90 PRACTICAL IRON FOUNDING 

When power is used it is chiefly compressed air in this 
country, and hydraulic power in Germany. 

Machinery for cleaning castings includes tumbling 
barrels, sprue cutters, pneumatic chisels, cold saws, 
emery grinders, and sand-blasting apparatus. All ex- 
cept the last, and the pneumatic chisels, which are 
operated by compressed air, are usually belt-driven. 
The countershaft used can be driven by a steam-engine 
or electric motor. The direct motor-driven unit is, how- 
ever, gradually coming into favour. 

In the foregoing remarks the foundry has been re- 
garded as an isolated unit. But very often it is one de- 
partment among several of equal importance in a great 
engineering works, and then the question of power is one 
which embraces the works as a whole. In such a case 
one large power house may supply electric current to all 
the shops, where it is taken up by motors located as 
seems most desirable. 

The large works also is favourable to the best possible 
adaptabilities of power, because not only electricity, but 
also hydraulic and pneumatic plants are, of necessity, 
installed. The boiler shop must possess the last two. A 
stamping shop must have either hydraulic or steam or 
pneumatic power, often two of them if heavy and light 
work are both being carried on. In such works the 
foundry will be highly favoured in being able to utilize 
the best possible agents for its various services. 

Heating and ventilation. — The heating and ventilation 
of foundries have too often been neglected. Modern 
buildings are usually lofty, the areas are large, and large 
end doors, which are frequently opened, are essential; 
and these conditions, with louvre ventilation in the roof, 
or alternatively swinging sashes, are frequently sufficient 



THE SHOPS, AND THEIR EQUIPMENT 91 

in foundries of large dimensions, such as those com- 
prising two or three adjacent bays. Hence, compara- 
tively few foundries have provision either for ventilation 
or for heating, where the temperature in the coldest 
weather seldom drops lower than about 18 degrees or 20 
degrees Fahr., nor remains long at that. In the northern 
United States and Canada, where temperature is fre- 
quently a good way below zero for long periods, warming 
is imperative, and ventilation is made a part of the 
system. 

The plenum system, using a blower circulating cold 
air on the outsides of banks of steam pipes which con- 
stitute a heater, and discharging it through ducts within 
the building just above head room, is the ideal system. 
The temperature within the building depends on numer- 
ous conditions which have to be weighed carefully, such 
as cubic capacity, amount of glass, frequency of change, 
difference between the outside and inside temperatures 
required, the latter being usually in the winter 50 degrees 
to 55 degrees Fahr. for foundries. Thence the tempera- 
ture to be imparted to the air at the heater, the size and 
number of revolutions of the blower, the sizes of pipes 
and ducts and their numbers are calculated, being the 
work of engineers who make this a specialty. 

Small steel converters. — Steel castings are now used 
instead of those of iron for so many purposes where 
lightness has to be sought, as well as strength, that a 
steel foundry has become a frequent annexe to the iron 
foundry. The steel firms can supply castings, but delays 
and expense are lessened when the iron foundries make 
such steel castings as are required for their own use. 

This practice has been fostered and developed by the 
growth of the baby or small steel converters, the Tro- 



92 PE ACTIO AL IRON FOUNDING 

penas being generally used. The choice lies between 
these small converters and the small open-hearth furnace, 
since the ordinary large converters handle quantities of 
metal too great for the small steel foundry. Moreover, 
the grade of metal is not so easily controlled as is that 
in the small converter or the open-hearth furnace. 

A good deal might be said in favour of each system. 
The baby converter requires a rather large plant, as the 
metal has to be melted in a separate cupola first, and a 
turning or tilting gear, power-operated, is essential. The 
open-hearth furnace requires no such aids, but it must 
have regenerators. 

On the whole, it appears that the small converter 
plant is being installed very extensively on the ground of 
its great utility in small castings made in small quan- 
tities, articles which have previously been forged, or 
made in malleable cast iron, or in one of the bronzes, or 
in cast steel in the regular foundries. Quantities much 
smaller than the contents of even a small open-hearth 
furnace can be melted in these converters. There are, 
moreover, considerable numbers of small, self-contained 
melting furnaces suitable either for steel or the bronzes, 
furnaces of tilting type and having blast pipes, as the 
Schwartz and others. These are extremely simple, more 
so than the baby Bessemer designs and therefore adapted 
to conditions which might not admit of the laying down 
of such a plant. 



CHAPTER VI 

MOULDING BOXES AND TOOLS 

Flasks or moulding boxes are employed for enclosing 
either in part or entirely all moulds excepting those 
which are made in open sand. The lower portion of a 
mould may be in the sand of the floor, and its upper 
portion in a flask. Or the entire mould may be contained 
in flasks above the level of the floor sand. 

The upper portion of a covered-in mould is termed the 
top or cope, and the flask corresponding therewith is also 
termed the cope, or often the top part. The flask in the 
bottom, or that which lies on the floor, is called the drag, 
or bottom part. If there is a central flask, that is named 
the middle or middle part. These are shown in Figs. 29 
to 31. In this group. Fig. 29 is a cope. Fig. 30 a drag 
or bottom, and Fig. 31 a middle part. 

It follows from a consideration of the obvious functions 
of flasks that they must fulfil these main conditions — 
they must be rigid and strong enough to retain their 
enclosed sand without risk of a drop-out occurring, and 
their joints and fittings must be coincident, so that after 
the withdrawal of the pattern they shall be returned to 
the precise position for casting which they occupied 
during ramming up. 

Rigidity and strength are obtained by making the 
flasks of cast iron of sufficient thickness. Occasionally 
they are made in wood, this being a common practice in 

93 



94 



PRACTICAL IBON FOUNDING 



the United States and Canada, but the general practice 
here, and by far the better, is to use cast iron. The evils 
of a weak and flimsy flask are, springing during the pro- 
cess of turning over and of lifting, causing fracture of 
the sand to take place, and portions to fall out; and 
springing or straining of the cope at the time of casting, 
producing a thickening of the metal over the strained 




P 



-^ 



^ 



.T-l 



Fm. 29.— A Cope. 



area. A flask should not be excessively heavy, but at 
least it requires to be strong and rigid. 

Various devices are adopted in order to ensure the re- 
tention of the contents of flasks. Chief among these are 
the bars or staijs by which they are bridged, A' A^ in 
Figs. 29 and 30. These are ribs of metal usually cast 
with the frames, though sometimes bolted therein, to be 



MOULDING BOXES AND TOOLS 



95 



detachable therefrom. They are arranged for the most 
part at equi-distant intervals. Their forms differ. Thus 
the typical bars for bottom or drag flasks are flat, 
Fig. 30, A\ their function being the retention of the 
sand which lies thereon, and which but for the bars 
would mingle with the sand on the floor. Only in the 
case of special flasks, as for example those used for pipes, 




n 



liT" 



D 



k 



^ 



V///.! "y^-.f -T^yAT 



^i 



Y/A iVi'.i Z£. 



..cJ 



Fig. 30.— a Drag. 



columns, and for repetitive work (Figs. 32 to 34) in 
which the bars follow the contour of the pattern, is this 
practice departed from. The bars in the cope (Fig. 29, 
A ^) are made on an essentially different plan. Here they 
are never flat, but always vertical, being rather of the 
nature of ribs than of bars. For^general work they are 
parallel, as in Fig. 29, but for special work their lower 
edges are cut to the contour of the pattern which they 



9(J 



PRACTICAL Ih'ON FOUNDING 



cover (Figs. 32 to 84), but kept to a distance of } in. 
or f in. away from the patterns. They are always cham- 
fered also, Fig. 29, because if left flat, the sand lying 
immediately underneath the bars ^Y0uld bo insufficiently 
rammed. Being chamfered almost to a knife-edge, the 
full pressure of the rammer is exerted immediately un- 
derneath the bars, as elscAvhere. 

M /A_.^ 



UbJ 



Lk- 



]Li 



w 



i^^ 



IF 



J: 



D 



sl^ 



Fig. 81. — A Middle. 



riy 



There are no stays in middle parts excepting for some 
special work. Middles for general work are always left 
clear of bars, as in Fig. 31, because they have usually 
to contain a zone of sand only, the central portions 
being open. To retain this zone of sand, rods and lifters 
are employed, the function and mode of use of which are 
described at p. 147. Lifters are also employed in the 
cope. A rib is cast around the inner bottom edge of a 



Fig. 23 
Heavy Ladle 




PLATE IV 



Fig. 24 
Carriage Ladle 



Fig. 25 

Bogie Carriage 

Ladle 



Sea 2). 69 




[Facing p. 96 



-La. 









<- 



^ 



cii 



a 




M 
O 

w 

M 

I 

I 

00 

6 

M 




m 



98 PRACTICAL IRON FOUNDING 

middle, Fig. 31, B, to assist in the retention of the 
sand, and also as a convenient support for the rods 
which help to carry the lifters and the sand. 

Flasks are always cast with a very rough skin, the 
better to retain their contents. They are frequently 
made in open moulds, no blackening is used, and their 
inner faces are often purposely hatched up to increase 
their adhesive powder. 

The coincidence of the joints of moulds is effected dif- 
ferently in the case of work which is bedded in, than in 
that which is turned over. Thus, the mould being bedded 
mainly in the floor, the cope is set by means of stakes of 
wood or iron; but being turned oveVj the flasks are fitted 
with 2)ins. 

In the first method, one example of which is shown on 
pp. 165 to 169, the pattern having been bedded in, and 
rammed up as far as the joint face, parting sand is 
strewn thereon, and the cope lowered into its position 
for ramming. Before being rammed, however, its per- 
manent place is definitely fixed by the stakes, which are 
driven deeply down into the sand of the floor alongside 
of the lugs, Fig. 29, E, E, or other projections standing 
from its sides. See also p. 174, Fig. 97, D. Being then 
rammed, and afterwards lifted off for withdrawal of the 
pattern, and cleaning and finishing of the mould, it is 
returned and guided to its original position by the stakes 
in the floor. 

In the second method the lugs cast upon the sides 
of the flask parts have holes drilled to correspond 
with each other, and long turned pins are bolted into 
the lugs which are lowermost, and pass into the corre- 
sponding holes in the lugs above. The more care which 
is taken with the fitting up of these lugs, the more accur- 



MOULDING BOXES AND TOOLS 



99 



ately will the boxes and consequently the mould joints 
correspond. The length of the pins should be settled 
with reference to the nature of the work. In any case 
the pins should enter their holes before any portions of 
the opposite mould faces come into contact. Unless the 
pins guide the closing mould there is always danger of a 
crush of the sand occurring. In shallow flat work, 
therefore, the pins may measure no more than 3 in. or 
4 in. in length. But in work having deep vertical or 





c 3 

Fia. 34. — Section of 
Column Box (Fig. 33). 



Fig. 35.- Pin and 
Cottar. 



diagonal joints the pins may require to be 8 in. or even 
10 in. long. The practice is usually to make the pins 
point upwards. Thus, in Figs. 29, 30, and 31, the parts of 
the flasks are represented in their correct relations for 
super-position at the time of final closing of the mould. 
The drag (Fig. 30) has its pins G, G, pointing upwards 
ready to enter into the lugs C\ C\ of the middle (Fig. 31). 
The pins F, F, of Fig. 31 also point upwards to enter 
into the lugs E, E, of the cope (Fig. 29). 

The best method of securing the pins is with cottars 
(Fig. 35); sometimes, however, in deep moulds cast 



100 PBACTICAL TBON FOUNDING 

vertically, the pins are short, and the ends are screwed 
and the tightening is effected with nuts. 

AVhen liasks are retained in position with stakes, cot- 
taring or screwing cannot of course be effected, yet great 
counter pressure is necessary to prevent a cope from 
being strained and lifted at the time of pouring. Wcicflits 
are therefore employed for this purpose, the amount re- 
quired being estimated roughly according to the area of 
the mould, and its depth from the pouring basin. 

If the contact area of a cope measures four feet 
square, and the height of the pouring basin is one foot 
above it, the amount of weight required by calculation 
to keep it down, including its own weight, will be 
48" X 48" X I'l" X "^2()i^ lb., the latter being the weight 
of a cubic inch of iron. This would give 7,121 lb. re- 
quired for loading, or over 3] tons. Actuall}^ a moulder 
seldom attempts to calculate the weight necessary to 
load a flask properly, because so many other conditions 
have to be considered besides the simple laws of hydro- 
statics. There is a good deal of pressure due to momen- 
tum to be taken into account. ]\[etal poured directly 
into the mould will exercise more straining action than 
that led in at the side. Eapid pouring again will cause 
move momentum than slow pouring. Hot metal will in- 
duce more strain than dead metal. Risers relieve strain. 
The moulder, therefore, loads according to the best of his 
experience and judgment, and not by calculation merely, 
which alone would often lead him astray. 

There are numerous minor attachments to flasks, used 
both for general and for special purposes. All flasks re- 
quire to be turned over, either for ramming, or for clean- 
ing up of the mould. For this purpose handles are 
provideil in the small tlasks, and middles. Fig. 31, F, and 



MOULDING BOXES AND TOOLS 101 

swivels in larger ones, Fig. 30, H, and Figs. 32 and 33. 
The swivels rest in slings depending from a cross beam, 
the beam being suspended from the crane the while. 
Since handles and swivels require to be very firmly 
secured in place, they are not only made of wrought iron 
and cast in position, but the metal is increased around 
that portion which is cast in, as shown in Figs. 29, 30, 
31, 32, and 33. 

There are other attachments, as handles, Fig. 33, B, B, 
for turning over flasks which are too long to be slung in 
the crane in the manner just noted, and for lowering 
them into the foundry pit for vertical casts. There are 
also flanges, C, C, in the same figure, for the attachment 
of back plates, that is, plates of cast iron bolted to the 
backs of deep flasks which have to be poured vertically, 
and which are subject, as all deep moulds are, to enorm- 
ous liquid pressure. The back plates prevent all risk of 
the pressure forcing out the molten metal, and so pro- 
ducing a waster casting. 

The forms of flasks vary widely, being rectangular, 
both square and oblong, and having ordinary, or special 
bars. Or, cope and drag may be precisely alike, and 
bars be alike in each, as in Figs. 32 and 33, which repre- 
sent pipe and column boxes. Fig. 32 being for pipes, and 
Fig. 33 for columns. The sides are bevelled in Fig. 32, to 
economize the sand, and time spent in ramming, a con- 
sideration when large numbers of casts are required. 
In Fig. 32, and Figs. 33 and 34 the holes D in the ends 
are for the purpose of allowing the ends of the core 
bars to project through. Flasks are also circular for cir- 
cular work, or of irregular and unsymmetrical outlines to 
suit work of special character. In jobbing shops, flasks 
will be sometimes fitted with interchangeable bars bolted 



102 



PRACTICAL IRON FOUNDING 



in place. Pockets also are often fitted at the ends, which 
are then bolted on, to be removable, the object being to 
increase the length of the flask. Sometimes pockets are 
bolted on the sides to take branches, and holes are cut 




Fia. 36. — Wooden Snap Flask. 



through the flask sides next the pockets. In all these 
cases the question to be decided is one of relative cost, as 
between the expense of the alterations, and that of a new 
flask. Flasks cost little for making, and the metal is 
always worth nearly its first value for re-melting. The 



MOULDING BOXES AND TOOLS 



103 



dimensions of flasks will range from 6 in. to 12' 0" square, 
or from 1' Q" to 20' 0" long, if of oblong form. 

Sncq) flasks. — Figs. 86 and 37 show a wooden snap 
flask, made up^to about 14 in. square, with pins of tri- 
angular section, having provision for taking-up wear. 





Fig. 37. — Wooden Snap Flask. 



These are made of birch or other suitable hard wood, 1 in. 
to 1^ in. thick, by 3 in. deep, in standard sizes. As no 
bars or stays can be used, each side has two concave 
recesses cut longitudinally, so that the boxes can be 
lifted without risk of the sand falling out. The fast 
corners are bonded with ^ in. sheet iron running the 
whole depth. The hinge is made with ^ in. straps. The 



104 



PRACTICAL IRON FOUNDING 



snap at the opposite corner is of the latch type (compare 
with Fig. 38), and the latch cannot be locked in place 
unless the corners are in absolutely close contact. 
This fitting is of brass, to avoid rusting up. The pins, 
which are also of brass for the same reason, are seen in 
Figs. 36 and 38. The pin is cast on an angle bracket that 
is screwed to the side of the top box, and fits through a 
a hole in another angle bracket on the bottom box. This 
bracket is made in two pieces, one of which is screwed 
to the box side, and the other attached to the horizontal 



■^v 



# 



V 



r@ 



CP^ 



W 




Fig. 38. — Details of Snap Flask. 



portion with two set bolts, over which slot holes in the 
adjustable piece slide^ permitting the taking np of wear. 

The pattern plate. Figs. 39 and 40, has triangular 
holes to receive the pins, and lugs on oj^posite corners 
for the purpose of rapping and lifting it by. The plate is 
of cast iron, 4- inch thick, planed on both sides. That 
shown in the figure has pattern parts on both sides, and 
ingates and runners on the top, Fig. 40. Presser boards 
for top and bottom, Fig. 41, stiflened with battens, fit 
freely inside the flask parts. 

A man and a boy operate a machine and set of moulds 



MOULDING BOXES AND TOOLS 105 

thus : The sand bemg mixed and damped and thrown in a 
heap at the side of the machine, the man commences work 
by placing the complete flask on the machine upside down 
— that is, with the pins pointing downwards — and lifts 
off the upper part, Fig. 36 (the bottom part in the com- 
pletelj^-rammed mould). The pattern plate is next laid 
on the joint face of the box part — with the deepest por- 
tion of the patterns facing upwards — and the upper part 
is replaced over the plate, the pins passing therefore 
through the plate and the lower one. The lad now throws 
sand into the box from the heap, while the man tucks 
the sand round the patterns with his hands. When the 
box part is filled, the sand is strickled off level, and the 
bottom board, or carrying-down board, Fig, 41, is laid 
upon the strickled surface. 

During this time the table or platen has been standing 
out clear of the presser head, but now a catch on the 
right-hand side of the machine, which has hitherto re- 
tained the table in place, is released, and the table is 
moved to bring the mould under the presser head. The 
lever is pulled sharply once or twice, raising the table 
and bringing the press board in contact with the head, 
compressing the sand, and sending the presser board 
between the box sides to a depth of from f in. to 1 in. 

Keleasing now the lever and the catch, the table moves 
forward and remains locked in a slot, bringing the box 
clear of the head. The man now turns it over, and the 
same operation of shovelling in, tucking, and strickling 
off the sand is gone through. The second presser board, 
now put on, carries the pattern cup for the ingate, which 
comes plumb over the ingate boss on the pattern plate. 
The same operation of running the table back and press- 
ing is repeated. 



106 



PRACTICAL IRON FOUNDING 



The table is next drawn out, the pressing board lifted 
off, leaving the impression of the pouring cup, which is 
now connected to the boss beneath by removing the sand 
with a tubular cutter. The lad next raps the projecting 
lugs at the corners of the pattern plate, and the man 
lifts the top part of the flask and places it on edge on a 
stand at the left-hand side of the machine. The lad raps 
the plate on the top face, and the man draws it, together 



A 







L 



V 



Fig. 89. — Pattern Plate for Snap Flask. 



with the lower sections of the patterns, from the bottom 
part. The lugs, with their well-fitting pins, enable the 
man to give a steady perpendicular lift until the patterns 
are quite clear of the mould. 

At the next stage the halves of the moulds are closed, 
standing on the bottom press board. The catches or 
snaps at the corners are released, and the flasks are 
opened on their hinges away from the mould, which is 
left standing on the board. This is then carried away 



MOULDING BOXES AND TOOLS 



107 



bodily and laid on the floor, and other similar moulds 
made, so that instead of a separate flask for each mould, 
one flask suffices, and as many bottom boards as there 
are moulds in a day's work. 

As there is no cottar ing of pins done, the moulds are 
kept closed by flat weights — one to each mould. Each 
covers the area of the mould and has a centre hole 
through which pouring is done. They are lifted by 



^ 




'ZJ 



Fig. 40. — Pattern Plate for Snap Flask. 



wrought-iron eyes cast in at opposite ends. About six 
weights suffice, because they are being moved from the 
first moulds poured as the pouring is being done on the 
fifth or sixth. The lad does this as the man pours. 

With regard to the effect of the pressure of metal on 
moulds unsupported by flasks, no difficulty occurs unless 
the moulds contain rather heavy castings. In cases where 
their weight does not exceed about 12 lb. there is no 
trouble. In heavier ones, up to about 28 lb. weight, the 



108 



PRACTICAL IRON FOUNDING 



moulds are enclosed with sheet-iron binders, which are 
slipped over the moulds. As light castings form the 
staple in many foundries, the saving in cost and storage 
room for flasks mounts up. Actually a man and a boy 
can put down from 150 to 200 boxes in a day, besides 



?^ 



m 



Fig. 41.^ — Presses, Board, 

getting the sand ready, coring when required, casting, 
and knocking out the castings. 

The illustration. Fig. 42, is drawn to give the relation 
of the box parts to the pattern plate, shown between 
them, and the top and bottom presser boards. 







m 



m. 



Fig. 42. — Shows Relation of Box Parts to Pattern 
Plate and Boards. 



Tools. — The small tools used by moulders, and mostly 
provided by themselves, though not numerous, are very 
characteristic of the work done. Foremost among them 
is the rammer, varieties of which are shown in Fig. 43, 
A being the usual form of pegging rammer, B another 
form, C and D flat rammers. A and B are employed for 



MOVLDING BOXES AND TOOLS 



109 



consolidating the sand in narrow spaces, and generally 
for all the earlier stages of ramming, C and D being 
used only for final flat ramming, or finishing over of 
surfaces. E shows the manner in which the flat rammer 
is handled, a wedge at the lower end being driven home 
by the forcing down of the handle into the socket of the 
rammer head. 



B 





Fig. 43. — Rammers. 



Vent wires are shown at Fig. 44, B being a small 
pricker or piercer, as it is sometimes called, the other, 
A, being larger and requiring considerable force to use. 
The smaller wire, which may be from ^ in. to -i% in. in 
diameter is employed for piercing the sand in the imme- 
diate vicinity of the pattern with innumerable holes, all 
leading into larger vents, or into the gutters in the joint 
faces. The larger wires will range from 



J in. to fin. and 



110 



PRACTICAL IRON FOUNDING 



are used for ventino- down to cinder beds underneath 
flasks, and around the edges of deep patterns, bringing 
off the vents from the smaller channels. 

The trowels (Fig. 15) are in perpetual request for 




FiOr. 44. — Vent Wires. 



Fig. 45. — Trowels. 



smoothing or sleeking the surfaces of moulds, for spread- 
ing and smoothing the blackening, and for mending up 
broken sections of moulds. They are also employed for 
Jiint'mii joints of dry sand moulds, for marking lines on 



m 



V\r,. k). — Cleaner. 



sand faces, and are improvised foi* many purposes beyond 
those for which they are legitimately designed. ^1 is the 
common }i('((rt shape, 7> the ^(luare trowel, and C the 
combination, or Jicurf (iiid f<qiiart' form. 

Fig. 46 is a clciohr, a tool used for mending up and 







iJ 

o 
o 
Eh 

I— I 

K 
m 

M 



6 

M 




112 PRACTICAL IRON FOUNDING 

smoothing the deeper portions of moulds which cannot 
be reached by the trowel. 

The remaining figures (47) illustrate finishing tools. 
A is a square corner sleeker^ also spelt slicker, or slaker. 
J5 is a similar tool, except that one face is adapted for 
sweeps, hence called flange corner sleeker, (7 is a head 
tool or smoother, or pipe smoother, for smoothing the im- 
pressions of beads or sweeps of that section. D is a 
holloiv head. E is a spoon tool, i^ is a square or flange 
bead, (r is a head tool curved lengthwise. H, I, J, are 
flange tools, K, K, hoss tools. L is a Button sleeker or 
hacca hox smoother. M an oval pipe sleeker. N another 
pipe sleeker. These tools, with a rule and calipers, com- 
plete the private kit of a moulder. 

Other aids. — The general appliances, used in moulding, 
omitting those of the nature of machines, and those not 
directly employed in moulding, are shovels, lamps, 
riddles, sieves, buckets, water-cans, bellows, oil-cans. 
Shovels are used for sand-mixing and box-filling, lamps 
for throwing light into the darker recesses of moulds; 
the uses of riddles and sieves have been described, 
p. 23; buckets and water-cans are used for damping sand 
and swabbing moulds, bellows for blowing away parting 
sand and loose particles generally, oil-cans for pouring 
oil over chaplets, and on damped corners and sections of 
moulds to prevent the metal from bubbling and caus- 
ing scabs. These are all provided by the firm for 
general use. 



CHAPTER VII 

SHRINKAGE — CURVING — FRACTURES FAULTS 

Though the laws which govern shrinkage and curving of 
castings are somewhat obscure and uncertain, yet little 
difficulty is experienced in making allowances sufficiently 
exact for all practical purposes. Curving, however, as a 
rule gives greater trouble than shrinkage. 

The linear shrinkage of all ordinary iron castings is pretty 
constantly i^in. in 15 in. If, however, a casting is exception- 
ally light a rather greater allowance should be made, say 
^in. in 12 in., if unusually massive a smaller allowance, say 
1^ in. in 18 in. or 20 in., and in the case of a very massive 
solid casting the shrinkage appears to be almost nil A 
casting will apparently shrink less in the direction of its 
depth than in that of its length or breadth, but this is 
apparent rather than real, for a very deep casting will 
be found on careful measurement to have shrunk to the 
normal extent, showing that the apparent diminution in 
the vertical shrinkage of shallow castings is due to second- 
ary causes, chief of which is the springing or straining 
upwards of the cope by reason of liquid pressure. Cast- 
ings, the central portions of which are hollowed with 
numerous dried sand cores, and which are rendered 
rigid by ribs, or which are plated over, do not, as a rule, 
contract so much as those in which shrinkage is unim- 
peded, as for example in those cases where the centre is 
cored with green sand, or when metal is not massed 

I 



114 PRACTICAL IRON FOUNDING 

heavily about the centre. Thus, a gear wheel with arms 
will shrink less than a mere ring of teeth. Hard white 
iron also shrinks much more than the soft gray kind — 
roughly, twice as much — and strong mottled iron occu- 
pies a position about midway between the other two. 
When, therefore, it is stated that the shrinkage of iron 
equals | in. in 15 in., that is given as a good average, 
^ in. in 12 in., as sometimes stated, is not correct for 
ordinary work, but only so for the lightest castings, for 
which it is about a proper average. 

Of the curving of castings the barest summary need 
be given. An excess of metal in the form of a rib on one 
side of a long casting invariably induces a concave cur- 
vature on that side, the concavity increasing with the 
amount of disproportion. Where there are two flanges 
of unequal thickness in a long girder or girder-like casting, 
concavity will result on the side of the heavy or tJiick 
flange. When, in a column or pipe the metal is of un- 
equal thickness, the casting will go concave on the side 
where the metal is thinnest — the direction of curvature 
being precisely the reverse of that which is witnessed in 
a girder or a ribbed casting. Both sets of facts are, 
however, consistent with one another. The explanation 
appears to be: that in the column the disproportion in 
thickness is so slight, that cooling, and the initial shrink- 
age, and consequent curving of the thin side remains 
permanent, while in the case of the girder, though the 
thin flange shrinks and curves first, yet suflicient heat is 
transmitted from the heavy flange through the web to 
maintain the thin flange in a semi-plastic condition. 
Cooling slowly therefore under restraint, its crystals 
remain somewhat large and its texture open, and its 
total shrinkage is thereby- diminished. Finally, the 



SHRINKAGE— CURVING— FRACTURES, ETC. 115 

heavy flange shrinks to its full extent, more so than 
the thin one, the shrinkage of which has been delayed 
and diminished. The heavy flange consequently becomes 
concave, pulling the thin flange, still at about its own 
temperature, convex. Figs. 48 to 51 show typical sec" 
tions, which, if long relatively to their cross sections, 
will infallibly become concave in cooling on the sides 
marked A. This curvature is termed camber, and a 
pattern is cambered to the precise amount by which its 
casting is expected to curve, and in the opposite direction. 
It is, however, only possible to design patterns to neu- 
tralize the curvature in unsymmetrical castings by much 



A 



i 



Fig. 48. 



"^^ZZ^ A 



1 

A 




Fig. 49. Fig. 50. 

Sections liable to Curve. 



Fig. 51. 



observation of actual cases, experience, and very often 
in new work, some tentative measures being the only 
guides; all depends on relative proportions, that is on 
lengthy as well as on cross section, a vital point which 
must be ever borne in mind. 

TJie Fracture of Castings. — Iron castings break by 
reason of the unequal tension which occurs between 
adjacent parts. As a mere statement this seems simple 
enough, but so many causes contribute to such a result 
that the reasons for fracture are not always apparent. 

By unequal tension is understood the internal stress 
which is set up by the skrinkage of metal during its 
cooling down after pouring. This affects castings in two 



116 PRACTICAL TBON FOUNDING 

ways, one being that \vhich results from the arrange- 
ment of the crystals, the other that of the thick and thin 
sections which are tied together in close proximity. The 
problems involved in these two cases dilier, and yet they 
are in some degree related. The tirst is readily under- 
stood both in theory and in its practical applications: 
the second is not so easy of recognition. Castings will 
sometimes fracture in a manner which is not readily 
explained, as in frosty weather, though even then the 
reasons are generally traceable to a neglect of the two 
conditions named above, crystallization, and the proper 
proportioning. 

There is something w^liich almost savours of instinct 
possessed by the man who is able to design castings which, 
even though awkwardly shaped, will not fracture. It is 
not always practicable to produce ideal designs such as will 
meet with the approval of the moulder; but the latter 
can often secure safety even in undesirable shapes. The 
drawing office should always keep in close touch with 
the foundry when new designs are being got out. AVasters 
would often be avoided if this precaution were taken, 
apart from the unnecessary expense which is frequently 
incurred in the cost of moulding shapes, the designs 
of which could be moditied without detriment to the 
mechanism of which they form a portion. 

It is hardly necessary to remark that crystallization 
explains why sharp angles are or should bo avoided, as 
far as possible, in castings. In chilled castings the 
planes of crystallization are most apparent. But they 
always exist in ordinary gray iron castings, and the 
sharp angles which occur in rectangular shapes (Fig. 52) 
invite easy fracture. In curved outlines (Fig. 53) there 
are no sharp planes of separation. Hence curved designs 



SHRINK A GE~CURVING—FRA CTURES, ETC. 1 1 7 

are not only more graceful, but stronger than square 
ones, and the larger the curves the better. But square 
designs, with a small radius, combined with bracketings, 
are also strong. But the bracketing should be continuous 
with the main body of metal, and not take the form of a 
cross-tie, which is weak. Examples of the latter occur 
in gratings and other objects. If the crossing-pieces are 
of slight section, and the surrounding portions are 
massive, the former are almost certain to become pulled 
away from the latter in some degree. The results will 
be similar if the ties are of large section and the sur- 





. „, riTrnrr. 

^i];li!llu;il,iiM;:i:!iiJL 



Fig. .52. Fig. 53. 

Crystallization in Castings. 



roundings slight. In the direct pulls exercised by shrink- 
ages at right-angles, the lines of cleavage of the crystals 
will be weak sections that will readily part in two. But 
if a large flowing curve is inserted, to form the union, 
the shrinkage will be distributed around that, and the 
section itself will be strengthened, because there will be 
no abrupt lines of crystallization present. 

But a limit soon comes to the strength which a proper 
disposition of the crystals affords, a limit at which 
unequal shrinkage will tear contiguous sections asunder. 
Here a considerable experience becomes necessary to 
enable a man to design forms that will not fracture. 
The presence of thick and thin sections in close proximity 



118 PRACTICAL IRON FOUNDING 

will not alone induce fracture. The safe condition is that 
they are free to shrink in on themselves. They will only 
fracture if they are tied, and bound fast, so that their 
shrinkage is thereby prevented. This will happen if the 
casting in itself is of improper form, or if, though cor- 
rectly proportioned, it is prevented from shrinkage in its 
mould. The first is, of course, by far the most frequent, 
but the latter is rather common. 

A good object lesson in the causes which produce 
fracture is the familiar cast-iron belt-pulley. This 
is safe if properly designed, excepting at excessive 
rates of revolution; but, if disproportioned, it w^ill 
fracture in the mould in cooling, or afterwards, when 
being turned, or w^ien being keywayed, or while working, 
all these being not uncommon mishaps. The reason 
why pulleys in particular are so sensitive is because the 
metal is so slight that it cools more rapidly in rim and 
arms than in the boss. The boss is the chief source of 
danger. A slight difference in its thickness makes the 
difference between safety and risk. Thick bosses, there- 
fore, should never be used on light pulleys. The extra 
thickness required round the keyway should be added 
as a keyway boss. If a boss is very long it is also 
risky, and then the bore should be enlarged — chambered 
out, at the central portion. And if the recessed pulley is 
a loose one it may be bushed right through, covering up 
the chamber or recess. 

But, after the boss, a rim too thick causes risk of 
fracture. For if the rim is thin it will become broken 
and pulled inwards by the fracture of one arm or more. 
If, on the other hand, it is thick, it will break oft' an arm 
or arms. For this reason again, the allowance for 
turning must not be excessive on a rim already properly 



SHRINKAGE— CUBVING—FBACTUUES, ETC. 119 

proportioned, else the pulley may fracture in cooling. 
And if a rim is cast of medium thickness, even though 
it may not fracture in the mould, it is liable to do 
so while being turned, when it arrives at that stage 
where its strength is overcome by the tension of the 
arms. 

Lastly, the arms may be too light, in which case they 
will fracture under the pull exercised by the cooling 
boss. Or they may be too heavy, and cause fracture of 
the rim. In belt-pulleys, therefore, the proportioning 
of each part must be nicely adjusted if fracture is to be 
avoided. 

And what occurs in a pronounced degree in pulleys 
happens in a less marked extent in toothed wheels, in 
the centre castings of crane beds, and in the castings for 
crane foundations. Heavy bosses next light arms are 
ever a source of danger, and there comes a limit to 
bracketing and the use of curved and filleted connections, 
beyond which fracture is likely to result, either during 
cooling, or tooling, or in service. It is certain that there 
are large numbers of castings in use which are always 
perilously near fracture, and which only await the appli- 
cation of some sudden and unusual stress to do so. The 
effects of and the amount of such tensile forces are 
often very apparent in the bosses of toothed wheels, fly- 
wheels, heavy pulleys, and beds, which have to be 
divided or split with plates, to be either bolted or bonded 
together subsequently. The divided bosses are often 
drawn apart in cooling, leaving the divided portions 
^ in., or even more, wider than they were at the time of 
casting, an ocular demonstration of the stresses which 
occur in cooling. This splitting is adopted as a neces- 
sary precaution against fracture, though it increases the 



120 PRACTICAL IRON FOUNDING 

expense and entails bonding or bolting, and is often 
unsightly. But it is better than a fractured casting. 

Although mass in certain parts menaces the strength 
of some castings of the class which we have been con- 
sidering, there are many examples in which mass is 
necessary for strength. It occurs in those cases in which 
large sections being unavoidably adjacent, parts must be 
suitably proportioned. A familiar example of this kind 
occurs in spur-wheel castings. When the arms of 
these are made of J. -section, as when moulded from fall 
patterns, these are more liable to fracture than when 
the arms are of I -section, and the rim of the Q- section. 
In the latter case the sections are all about equally 
proportioned, and such wheels seldom break under severe 
stresses. 

In the second place, if the shrinkage of a casting is 
artificially hindered to any important extent it is liable 
to fracture. This is especially likely to happen in large 
loam moulds, and is the reason why courses of loam 
bricks are inserted, and why the hard bricks must 
frequently be partially or entirely dislodged before the 
casting has arrived at the black-heat stage. Loam bricks 
in large cylinder cores are built in one, two, or three 
vertical courses. They are also laid behind top and 
bottom flanges. In both cases they yield to and are 
crushed by the shrinkage of the metal, that in the cir- 
cumferential direction in the first instance, and the 
shrinkage in the vertical in the second. But for this 
precaution such castings would fracture by their own 
shrinkage occurring against unyielding bricks, more 
than one instance of which the writer remembers. And 
it is often necessary to remove even the loam bricks 
before the shrinkage has proceeded far. Sometimes 



SHRINKAGE— CUBVING— FRACTURES, ETC. 121 

nearly all the bricks are loosened and thrown down into 
the middle of the core while the casting is still shrinking 
— a hot job for the labourers, but a safeguard against 
tlie chance of fracture. 

Some plated castings are exceedingly liable to fracture. 
If a large plate is free to shrink it is quite safe: but if it 
is tied with several strong webs or ribs it is not so. I 
remember some bed castings which were plated all over 
at top and bottom, with only small holes to get the 
cores out of, and several of these broke in succession. 
The trouble was got over by substituting ribs for the 
plates, which again were too massive, and tied too much, 
and being unable to yield much in any direction they 
fractured about the central boss. The better plan, how- 
ever, is not to plate beds at top and bottom, but, even 
though the top is left solid, to cast ribs only on the 
bottom. And it is usually better not to insert dried sand- 
cores in such beds, but green-sand ones only, or, when 
practicable, to let the bed deliver its own green-sand 
cores. I remember some large circular bottom tank- 
plates for water-cranes which sometimes split in a radial 
direction. This was prevented by splitting them in the 
mould with plates and filling up the places with rust 
cement afterwards. The reason is clear. The major cir- 
cumference was so great that the shrinkage going on 
round there put the metal in excessive tension, and as it 
could not move towards the centre on the solid metal 
there, it parted. Here, too, the shrinkage was partly 
delayed by the presence of ribs and a deep facing round 
the edge. 

Faults and Wasters. — An engineer's specification for 
the quality of cast iron runs substantially as follows: 

** The castings shall be clean and sound, both extern- 



122 PB ACTIO AL IRON FOUNDING 

ally and internally, and shall be carefully fettled and 
smoothed. They shall be free from honeycombing, blow- 
holes, scabs, cold shuts, draws, and other defects. No 
stopping up or plugging is on any account to be per- 
mitted. No castings shall be made in open sand. Cores 
must be cast in accurately. No more than five per cent, 
variation in weight will be allowed on either side. The 
metal shall be remelted once in the cupola, and free from 
any admixture of cinder iron, or other inferior material. 
It shall be uniformly tough and close-grained. It shall 
be of such strength that a turned bar having an area of 
two square inches shall bear a tensile strain of not less 
than from 16,000 lb. to 18,000 lb. per square inch without 
breaking. A test-bar 3 ft. between supports, by 2 in. deep 
by 1 in. thick shall bear a cross breaking strain of not 
less than from 28 cwt. to 30 cwt., with a deflection of not 
less than | in. or J in. before breaking." 

Honeycombing. — Fig. 54 is drawn to illustrate the ap- 
pearance of a spongy top face of a column casting. The 
sponginess may be greater or less in extent than that in- 
dicated by the drawing; but the general appearance is 
unmistakable, and the term spongy or honeycombed ex- 
presses exactly that appearance. The holes will range 
from the size of a pin's head to that of a pea or a hazel- 
nut. When larger, they have gone past mere spongi- 
ness, and are termed blow-holes. Often, as in blow- 
holes, the w^orst does not appear on the surface — a film 
of metal conceals a lot of honeycombing. A foreman or 
an inspector will try the most minute holes with a bit of 
wire or a long pin, and often discover in that way that 
a very small hole on the surface will extend for several 
inches beneath the surface, opening out really into a large 
blow-hole. Such sponginess is almost invariably found, 



SHRINKAGE- CURVING-FRACTUBBS, ETC. 123 

when present, on the upper surface of castings, where 
the pressure is least ; seldom on the lower, where it is 
greatest. In some positions it is of relatively little 
moment; in others it should condemn the casting. 
Those parts which are subject wholly to tension, as the 
bottom flanges of girders, should never be passed if the 
honeycombing is at all extensive or deep. In the case of 
lugs •subject to tension, honeycombing, such as that 




O 



Fig. 54. 



Fig. 55. 



Honeycombing. 



shown in Fig. 55, is quite condemnatory, even though 
all the rest of the casting is perfectly sound. Honey- 
combing on column flanges is also serious, because the 
stability of a column largely depends on flanges, and 
the strain of the bolts is liable to pull such flanges off. 
Sponginess down one side of a column may or may not 
be serious, dependent on its extent and depth. A prac- 
tised observer can usually form a correct opinion about 
that by probing, and by general appearance; but when 



124 



PRACTICAL IRON FOUNDING 



columns have to be subjected to severe stress, it is better 
to condemn all which show any traces of sponginess. 
They can be cast well if the mould is properly vented, 
the metal clean, and sufficient risers put on. Minute 
cracks in columns have sometimes been pened over with 
a hammer. The same practice is resorted to when there 
are honeycombed surfaces, the hammer-blows closing 

them, and smoothing the surface 
over. The most satisfactor}^ test for 
the closeness of grain and freedom 
from sponginess of a column is the 
hydraulic, just as it is used in the 
case of water- and steam-pipes. 

Blow-holes. — The utmost care does 
not always suffice to prevent these. 
They are due to insufficient venting 
of the mould or core, to moisture, and 
to the entanglement of air in the 
molten metal. Ample venting and 
steady pouring, with the use of risers, 
are the best preventives of blow- 
holes. Unfortunately, they are ver}^ 
often concealed by a film of metal, as 
in Fig. 56. Hence the top faces of 
all castings — which can always be 
known by the marks left from cut-off runners, risers, and 
chaplets — should be tested with hammer-blows, when 
hollow sounds will indicate tlie existence of concealed 
blow-holes, and a sharp blow will break through the thin 
film. Another way to detect them is to thrust a fine wire 
in some of the suspicious-looking small holes when such 
are present, when it will often penetrate several inches, 
revealing the fact that there is a blow-hole beneath. A 




Fig. 56.— a Bloav- 

HOLE. 



SHRINKAGE— CURVING— FRACTURES, ETC. 125 

smooth skin will often conceal hidden faults of this kind. 
Fig. 56 illustrates an extensive blow-hole in section below, 
and its locality and extent are indicated by dotted lines in 
plan above. Such blow-holes seldom occur, exce^ot on the 
upper portions of castings. These often extend over large 
areas without any external indication of their presence, 
because a thin film of metal so frequently covers and en- 
closes them. They exist either with, or without associa- 
tion with general sponginess. As they generally occur on 
the top, and as they are often completely hidden, it is ne- 
cessary to test all castings along their top faces with smart 
blows from a hand-hammer. Such blows do no harm to a 
good casting; but they will either return a hollow sound or 
break through the skin,if large blow-holes are underneath. 
Blow-holes in castings are less serious when they occur 
in those portions subject to compression than in those 
subject to tension. A few blow-holes occurring at inter- 
vals in the former would not sensibly increase the risk of 
crushing; but in the latter they would be highly danger- 
ous. Blow-holes in the neutral axis of a casting are of no 
moment. This is illustrated by the fact that holes may 
be drilled in the neutral axis of a test-bar, and the drilled 
bar will sustain the same load as a solid bar : on the 
other hand, if the bar were turned upside down, bring- 
ing the thinner metal into tension, it would fracture 
quickly. The fact is also illustrated by the practice of 
lightening out a girder along the neutral plane. Spongi- 
ness on the compression side of a casting will slightly in- 
crease its deflection; but, all the same, it is risky to pass 
work in which blow-holes occur, even in localities subject 
to little or no tensile stress; because if a casting is blown 
in one place, it may also be so in another, of which no 
indications are visible. 



126 



PRACTICAL IRON FOUNDING 



Scabs. — An extensive scab is shown in Fig. 57 at a. 
These occur on all parts of castings — top, bottom, and 
sides. They are due to the washing away of sand caused 
by hard ramming, to weak sand, and bad venting. The 
fettlers may chip them off; but an inspector can see 
where such extensive chipping has been done, and all 
castings that show signs of much scabbing should be 
condemned. It is not because the scab has been cut oft", 
but because its presence is a sure indication that there are 
masses of sand, corresponding in size with the scab, im- 




FiG. 57. — Scabbing. 



bedded somewhere in the body of the casting. Such 
masses may or may not come to the surface. If invisible, 
they constitute a hidden source of danger. It is quite 
likely that the corresponding hole or holes are not to be 
found, being perhaps covered with films of metal, but 
there is no doubt about their existence somewhere. So 
that the presence of extensive scabbing is quite sufficient 
to condemn the castings in which it occurs as unsound. 

The causes of scabs are various. As just stated, hard 
ramming is liable to cause them. So also is using sand of 
too close texture, or working it too wet. When ramming 
a mould, regard must be had to the nature of the casting, 



SHRINKAGE— CURVING— FBACTUBES, ETC. 127 

and the particular section of the mould which is being 
rammed. Metal will not lie kindly on a hard bed, but 
will bubble, the air not getting away with sufficient 
rapidity, and bubbling will result in the detachment of 
flakes of sand, and consequent scabbing. If, on the con- 
trary, the sand is rammed too softly, the pressure of the 
metal will produce lumpy castings. The moulder has 
therefore to ram the sand sufficiently hard to resist the 
pressure of metal, yet so soft that bubbling shall not 
take place. The practical result is a kind of compromise. 
The lower stratum of sand is rammed hard, and freely 
vented, and an upper stratum of an inch or two in thick- 
ness is rammed more softly. The metal, therefore, lies 
upon a comparatively soft cushion, which is supported 
by a firm, well-vented backing. The lower portions of 
moulds are not as a rule rammed so hard as the sides 
and top, since the gas can escape more readily from the 
latter than from the former. A hard-rammed mould will 
be productive of less risk in the case of a heavy than in 
that of a light casting. Another cause of scabbing is the 
leaving of risers and feeder heads open during the actual 
pouring of metal. 

Choking of vents will produce scabbing, hence the 
reason why the vent openings are always closed against 
the face of a mould. Excessive moisture in a mould will 
produce scabbing by the generation of steam in quantity. 
The moisture may be due to overmuch watering of the 
sand in the first place, or to the abuse of the swab at the 
time of mending up in the second. The amount of mois- 
ture in a mould should be just so much as is necessary 
to effect the consolidation of the sand — anything in 
excess of that is injurious. Too much sleeking with the 
trowel also is injurious, and too thick an application of 



128 



PE ACTIO AL IRON FOUNDING 



blackening, whether wet or dry, followed by hard sleek- 
ing, is a fruitful cause of scabbing, the blackening and 
the sand beneath flaking off at the time of pouring. 

Cold Shuts. — Fig. 53 illustrates the defect which is 
termed a cold shut. Its presence should condemn any 
casting, no matter where it occurs. The casting is really 
as good as fractured where the cold shut occurs. It 
means this: that the metal has been poured cold and 
dead, or that the metal has had so far to travel in the 
mould that it has become chilled; consequently, when 

opposing currents meet, they do 
not mix as perfect liquids, but 
only to a partial extent. Being 
so cold, they form a joint or im- 
perfect union, much like a bad 
weld. These are also caused by 
using poor iron with no life in it, 
or by using iron badly melted, as 
well as by allowing iron to remain 
too long in the ladle before pour- 
ing. When only a moderate stress 
comes on the casting, the cold shut becomes the weak 
link in the chain. These shuts can usually be recognized 
by the rounded appearance of the edges along the irre- 
gular groove or fissure where the metals have met. 

Draws. — These must not be confounded with blow- 
holes, or with general honeycombing. Draws are, of 
course, sources of weakness; but they differ from blow- 
holes and sponginess, in cause and in characteristics. 
They are not due to the presence of air or dirt, and they 
are not, as a rule, visible on the surface. The better — 
that is, the stronger — the metal is, the more liable is it 
to draw. And the draws occur in the heart of the thick- 




FiG. 58.— A Cold 
Shut. 



SHRINKAGE— CURVING— FRACTURES, ETC. 129 

est parts of the casting. They are due to unequal rates 
of cooling, and to crystaUization; the outside of the 
casting sets firmly while the interior is still molten, or, 
at least, viscous. As the interior shrinks, the outside 
will not yield, and so the interior metal shrinks on itself, 
becoming drawn towards the outside metal. Then one of 
two things, or both, must happen: the crystallization 
will be large, coarse, "open grained," and proportion- 
ately weak, or a cavity will be left about the centre. 
Given a tough, strong iron, and great disparity in thick- 
ness of metal, favourable to the more rapid cooling of 
some sections than others, and the metal is certain to 
become drawn. Hence, what some people think must be 
a good strong casting is a weak and uncertain one. As a 
blow-hole and a draw are due to entirely different causes, 
so their appearances are quite different and quite unmis- 
takable. A blow-hole is bounded by smooth concave 
faces or edges. A hole caused by a draw always has sharp, 
jagged boundaries, generally of very irregular outline. 
As there are great differences in the dimensions of blow- 
holes, so there are in the dimensions of holes caused by 
drawing. Blow-holes merge into mere sponginess; draws 
diminish down to mere openness or extreme coarseness 
of crystallization. Some holes due to drawing are so 
large that two or three fingers may easily be inserted in 
them; others will barely admit a pin between the coarse 
crystals. Draws, like many blow-holes, are generally 
concealed until the casting fractures; but their presence 
is often indicated by a slight depression of the surface 
adjacent, or by the presence of a small hole leading from 
the surface adjacent into them. Blow-holes generally 
occur on or near the upper surface of castings; draws 
may occur anywhere, in the bottom as well as in the top 

K 



130 PRACTICAL IRON FOUNDING 

of the mould; in fact, they are often more likely to occur 
in the bottom. Thus, if a mould is of no very great depth, 
and it is fed during the period while the casting is setting 
with fresh supplies of molten metal over the parts where 
the metal is thickest, drawing will be prevented. But if 
there is thick metal in the bottom, the chances are that 
drawing will take place there. On the other hand, in a 
deep casting not fed, heavy metal in the bottom will not 
be likely to draw, because the superincumbent liquid 
mass will feed it; but the top metal will be likely to 
draw. 

All draws are preventible by some method or another, 
either by alteration of design, or by the adoption of cer- 
tain precautions on the part of the moulder. Engine 
cylinders are capital object-lessons in the drawing of 
castings. They are ahvays made of tough, stiff metal, 
and invariably in localities where there is much excess 
of metal some may be confidently looked for. So, too, 
are large weights, such as are often cast for test loads 
and for foundry use. In such weights there is always a 
depression on the top face, due to the internal shrinkage, 
and if such weights are broken, there is always a central 
cavity also, or else very open crystallization. Again, sup- 
posing a girder made like Fig. 59, and the light and 
heavy flanges are tied with ends or with cross ribs, the 
probability is that in the vicinity of the union of the ribs 
with the thick flange there will be a draw, as at rt, and 
depressions at h, c, c. In the case of this girder, having 
a very heavy bottom flange, and pockets. A, for trimmer 
girders cast on one side, and brackets, B, on the other, 
there is every chance of a draw occurring in the thickest 
part. Or, if an actual open space does not occur, the 
crystallization will be very open, as shown at a. The 



SHRINKAGE— CURVING— FRACTURES, ETC. 131 

obvious alternative is to lessen the mass of the bottom 
flange and to put smaller radii in the angles. In the 
case of the column head, Fig. 60, putting a straight core 




Fig. 59. — A Draw. 

through, the side A masses too much metal at that 
locality, and there will be a draw at a, with probably a 
very slight circular depression of metal on the outside or 
inside, and the column will not be any stronger — prob- 





Fm. 60. Fig. 61. 

Draws, and how to avoid them. 

ably weaker — than as if it were cored out to an equal 
thickness, as shown at B. 

Fig. 61, side A, shows the effect of a heavy belt and 
thick bracket in combination, in producing a draw. At 
side B, with the belt shown and bracket made no thicker 



132 



PBACTICAL IRON FOUNDING 



than the thickness of the metal in the body of the 
column, no draw will occur. 

In these instances there would not be any appreciable 
risk of fracture, because the top flange is free to shrink 
inwards; but in some cases the risk of fracture becomes 
serious. It is serious when thick and thin adjacent parts 
are so tied that they are not left free to shrink. Heavy 
mouldings on columns ought, therefore, always to be 
cored out, to leave approximately the same section every- 
where. 

The tendency to draw is lessened, and the strength of 



^ 



B 




Fig. 62. — Effect of a Radius. 



castings increased, by abolishing all keen internal angles. 
This rule is of universal application. The evil of sharp 
angles is seen chiefly in flanges which have to take the 
pull of screw-bolts. In Fig. 62 the flange A would be 
almost certain to fracture when under moderate stress 
only. The flange B would possess the maximum of 
strength. In the flange C the radius would be rather 
overdone, and the flange too thick. The two extremes — 
a very thick flange and a very large radius — would prob- 
ably cause the draw shown, and produce fracture under 
less strain than that which would be required to frac- 
ture B. There is no advantage in a very large radius. 
A small radius, even less than that shown at B, adds 



SHRINKAGE— GUBVING—FBACTUBES, ETC. 133 

immensely to the strength. The mere strength is not 
that chiefly due to the increase of metal, but in- 
directly to the regular or symmetrical arrangement of 
crystals when cooling, which occurs when there are no 
abrupt re-entering angles. When such sharp angles do 
occur, there is an abrupt break in the arrangement of 
the crystals, and it is along that line of abrupt break 
that fracture will occur. Hence it is a rule that no iron 
castings to stand stresses should ever be made with 
keen internal angles. They should be filled up and ob- 
literated with radii, hollows, or fillets, as they are vari- 
ously termed. In some positions the omission of these 
is not of much importance; but in others their omission 
will certainly ensure fracture. 

It is rather fortunate that the moulder's instinct 
prompts him to insert those radii in moulds when they 
are not put on the pattern; but as he will not incur too 
much responsibility, he generally breaks the edge with a 
hollow sleeker, which is much better than nothing at all. 
And many a flanged casting would be broken in the mould 
before ever it saw the light of day but for the precaution 
the moulder takes of digging away sand from between 
adjacent flanges or ribs, and from between flanges and 
box-bars, and so permits free shrinkage to take place. 
Without this precaution, the hard sand in the mould 
would prevent the full shrinkage from occurring, and the 
tension put on the casting by shrinkage stresses would 
be greater than the tenacity of the red-hot or black-hot 
casting. 

Lapping joints. — A column which has been chipped 
heavily along the flask joints should be carefully exam- 
ined, because that is due to the shifting of the flasks on 
one another, or to the bad mending of a broken mould. 



134 



PRACTICAL IRON FOUNDING 



It means that the metal will be thinned along the joints 
by the amount of overlap which has been chipped off. 
Lapping-joints like those shown in Fig. 63 are unsightly, 
besides detracting from the strength of the casting. The 
strength being measured by the diminished section at a, 
instead of at b, lap to the extent shown in the figure ought 
to condemn a casting, even though a sound one. In 
Fig. 63, ^ is a section through a true column, and B a 
section through one which has overlapped. Some very 
slight amount of overlap is almost unavoidable in job- 
bing work, for which special flasks and patterns are not 
made. But it should never exceed, say, ^V i^^-j or jV i^-) 




Fig. 63. — Lapping Joints. 



at a. When it becomes ^ in. or -{•^^ in., it is too much 
to be passed. If, in addition to the overlapping, the core 
happens to be out of centre sideways, then the thickness 
of metal will be still further diminished. Sometimes 
flanges overlap, as shown at C. Then, if they are faced, 
their thickness is reduced by the amount of overlap. 
If they have to bed on stone without facing them, they 
look unsightly. 

Pressure in toj) and bottom. — Owing to the marked dif- 
ference in the strength of cast iron in tension and com- 
pression, it is usual, when practicable, to cast those 
portions of work which are to be in tension in the bottom 
of the mould. All the advantage to be derived from closer 



SHRINKAGE— CUEVING—FBACTUBES, ETC. 135 

metal is thus secured. This is practicable in the case of 
girders subject to uniform stress in one direction only. 
But it is not applicable to columns on which the 
stresses are either uniform, or, if variable, acting in all 
directions indifferently at different times. Thus, for in- 
stance, in columns sustaining the girders of a bridge sub- 
ject to side wind pressure, the opposite sides of the col- 
umns will in turn be in compression and tension. This 
will be due to the varying directions of the wind against 
the girders, producing bending of the columns to one side 
or the other. Such columns should in theory be cast up- 
right, with heads. But it is seldom done, because more 
costly than the usual method of casting horizontally. 
Horizontal casting is prolific of several evils, unless very 
great care is exercised in moulding, coring up, and pour- 
ing, and in subsequent testing and inspection. A test- 
bar will give the strength of the iron in the column, but 
it tells nothing at all about the evils above alluded to. 

The reason why more porous metal occurs at the upper 
part of a casting than at the bottom, is because it is sub- 
ject to little pressure, while that in the bottom is sub- 
jected to a considerable liquid pressure, which effects its 
consolidation, making it closer and stronger. The deeper 
the mould the greater the pressure, and the sounder 
will be the lower parts of the casting. This is the 
chief reason why the supplementary metal termed 
"head" is cast upon much work that has to be tooled, 
such as engine cylinders, hydraulic cylinders and rams. 
All the spongy metal is in the head, and when this is 
turned or sawn off, the casting below is uniformly sound 
at top as well as at bottom. This sponginess is always 
present in some degree on the top parts of all castings, and 
that is why founders always try to cast parts which have 



136 PB ACTIO AL IRON FOUNDING 

to be planed or otherwise machined bright, in the bottom. 
If the top part of a casting is machined, it ahnost always 
turns out spongy unless special precautions are taken, 
such as running through a skimming chamber, or al- 
lowing an extra thickness to be machined off, or cast- 
ing several risers or flow-off gates. The first-named 
consists of a circular chamber set right in the way of 
the course of the metal, and which is so arranged as to 
impart a swirling motion to the metal, sending the lighter 
matters upwards into a riser above, and leaving only clean 
metal to pass on into the mould (see p. 155). The third 
named means that there is a slight flow-through of metal 
in the mould permitted, the lighter matters passing out 
into vertical channels or risers (see p. 160). But these de- 
vices do not wholly prevent sponginess. They do, however, 
effect removal of the scurf, and that is something, since 
the presence of this is a fruitful source of s^Donginess. 
But the greater natural porosity of the metal on the top of 
a casting cannot be wholly removed. 



CHAPTEE VIII 

PRINCIPLES OF GREEN SAND MOULDING 

This branch embraces much the largest proportion of 
cast work done, bemg not only cheap, but sufficiently 
good for all except some few special purposes. The mean- 
ing of the term green sand was explained on p. 6. The 
methods of moulding in green sand are broadly classified 
under three great divisions, namely, moulding in open 
sandf by bedding in, and by turning over. By one or another 
of these, all work which is made in green sand is accom- 
plished. 

Moulding in open sand signifies that the mould is un- 
covered on its upper face. In the closed moulds, the 
metal when poured is arrested at a certain definite stage 
by the face of the sand in the top or cope. This face may 
have any contour, irregular or otherwise, but the upper 
face of a casting made in open sand can only be truly 
horizontal, which fact at once limits the utility of open 
moulds. But in addition to this, the upper surface of a 
casting made thus is always irregular, rough, porous, 
unsound: irregular and rough, because the hot bubbling 
iron is not confined against a face of sand, but begins 
to set before the commotion due to the evolution of its 
heat, and of the gases and air, has subsided — porous 
and unsound, chiefly for this reason, and partly be- 
cause it is not cast under pressure, as are all closed 
moulds; the pressure in these being due to the height of 

137 



138 PRACTICAL IRON FOUNDING 

the pouring-basin above the surface of the mould. Cast- 
ings made in open sand are therefore only employed for 
very rough work, never for ordinary engineering con- 
structions. Moulding flasks, back plates, foundation 
plates, core plates, rough weights used only for loading, 
and similar articles are made in open sand. 

The main essential in this class of work is to have the 
mould perfectly level, a matter comparatively unim- 
portant in closed moulds. Hence, either a level bed of 
sand is first prepared, and the pattern or skeleton of the 
pattern, or sectional portion of the pattern, as the case 
may be, is laid upon this and rammed, or the pattern is 
bedded in and levelled during the process of ramming. 
Venting is seldom done except when the sand happens 
to be of very close texture, but the air comes away partly 
from the upper face of the casting, partly through the 
bottom sand. 

Usually an open sand mould is made f in. or -J in. 
deeper than the casting is required to be, and overflow 
channels are cut around the edges to carry off the super- 
fluous metal, and to indicate the proper time for the 
cessation of pouring. A good deal of work in open sand 
is shaped by the moulder himself with the aid of a few 
strips and sweeps only, but then it is the roughest class 
of moulded work done. 

Bedding in. — This signifies the moulding of patterns 
in the sand of the foundry floor, the position of the 
mould being in no respect changed from the commence- 
ment of operations until the time of casting. In this 
method it is obvious that the lower faces of the mould — 
those which are formed underneath the pattern — will 
not be easily rammed, and may be harder and softer 
in places. 



PRINCIPLES OF GREEN SAND MOULDING 139 

When work is bedded in, the sand is dug up and 
loosened to a sufficient depth, and into this the pattern 
is beaten with heavy wooden mallets, its top face, when 
practicable, being tested by the spirit level — usually in 
conjunction with winding strips. As soon as a very 
rough impression of the mould is thus obtained, an inch 
or two of facing- sand is strewn or riddled over the whole 
area, and the pattern is beaten down again. This ham- 
mering down of the pattern causes the sand to become 
harder in certain sections than in others — becoming 
hard, it also offers a certain resistance to the further 
bedding down of the pattern. This consolidated sand is 
therefore hatched up and loosened, and if need be, por- 
tions are removed with the trowel, or with the hands, 
until the pattern has been made to bed pretty nearly 
alike all over. Eecesses, pockets, ribs, flanges, and such 
like, when present, have to be filled in, by tucking the 
sand underneath and around them with the hands, the 
smaller rammer following afterwards where possible. 
When the sand is thus rammed and brought up level 
with the top edge of the pattern, it is scraped and sleeked 
off, and the joint face made ready for the cope. The face 
is then strewn with parting sand, and the cope put on, 
set with stakes, and rammed. 

Though these operations are in general outlines very 
simple, yet in their practical details they call for the 
exercise of as much skill on the part of the moulder as 
those involved in turning over. The difficulty in bedding 
in lies chiefly in the proper consolidation of the sand. 
If the sand is of unequal consistence, scabs and blow- 
holes in the harder portions will result, and swellings on 
the castings over the softer portions. 

Turning over. — This signifies that the face of the 



140 PRACTICAL IRON FOUNDING 

mould which is lowermost at the time of casting, is 
uppermost at the commencement of ramming, being 
subsequently turned over. By this method it is clear 
that the portion of the mould which is finally lowermost 
will be rammed as evenly and well as the upper portion, 
since it has already been in the top at the earlier stage 
of ramming: and it is evident that the consolidation of 
the sand over any given area will be more perfect when 
it has been rammed directly against a pattern, than 
when the pattern has been simply beaten down into a bed 
of sand. But it is also clear that since in turning over, 
the whole of the mould is contained in flasks, this 
method requires more box parts or flask sections, and 
increases the weight which has to be lifted by men, or 
with cranes, or travellers; and is therefore more expen- 
sive than bedding in. The larger and heavier the work, 
the greater the reason then why bedding in should be 
adopted in preference to turning over. In massive work, 
therefore, the preference is usually given to bedding in, 
but in moulds of small and of moderate size, and gener- 
ally for work of the best class, turning over is the 
method usually adopted. 

Figs. 64 to 67 illustrate the moulding of a trolly wheel 
by turning over. The pattern is first laid with its upper 
face downwards on a temporary cushion of sand in the 
flask. A, Fig. 64, which is presently to form the top or 
cope. A joint face is made, which may or may not be in 
the same plane as the joint edge of the flask, being de- 
pendent on circumstances. It is often convenient to slope 
the sand joint up or down when the relative depths of 
pattern and flask require it. The joint is strewn with 
parting sand. Upon this the flask 2>, which is presently 
to form the drag, is laid, Fig. 65, and rammed per- 



PRINCIPLES OF GREEN SAND MOULDING 141 



manently. The two flasks then cottared together, are 
turned over, and the bottom or drag B is laid in its 



ra 



h^. 



A.AmmaM 



II M II II 

'• l -. ^..--, -; 4L^-^J^i^^JJ.--al -J 






Fig. 64. 



B 



ll '^ 1 1 II 1 1 
;L.J..'o i >^,,4->.jj-^ ; ;-!-ky,ri,"j!s - ^ - -^j. 



& 






«gfi 



fllMII I 



B 



® 



Fig. 66. 




Fig. 68. 



Fig. 65. 




Fig. 69. 




PLAN 



Fig. 70. 
Examples of Turning over. 

permanent position upon a bed of levelled sand. The 
cope is lifted off, its loose cushion of sand knocked out, 
and the upper joint face of the drag smoothed over, and 



142 PRACTICAL IRON FOUNDING 

strewn with parting sand. Fig. 66 represents the mould 
at this stage. The cope is then placed on, swabbed, 
liftered, and rammed permanently with the runner pin 
in place. The flasks are then parted at the joint, the 
mould mended and blackened, cored, closed, and cot- 
tared, and the pouring basin C made. Fig. 67 represents 
the mould closed ready for pouring. 

The next illustrations. Figs. 68 to 70, are those of a 
three-parted mould. It is obvious that the groove of the 
sheave wheel there shown must effectually prevent de- 
livery if moulded in the same manner as the trolly wheel 
— that is, with a cope and drag only. Two parting joints 
are necessary to enable the pattern to deliver, and in 
addition the pattern itself has to be divided through its 
middle plane. Fig. 68 shows that stage of the mould 
which corresponds with the stage in the moulding of the 
trolly wheel seen in Fig. 64. The sand in A, Fig. 67, 
forms a temporary bedding only for the half-pattern, 
over which the drag B is rammed for permanence. The 
flasks A and B, then cottared together, are turned over, 
A is removed, and the sand knocked out, the exposed 
joint face of B is sleeked, and strewn with parting sand, 
the middle part rodded and liftered, swabbed with clay- 
water, and rammed approximately level with the pat- 
tern joint. Fig. 69. To sustain the weak narrow zone 
of sand which forms the pulley-groove, nails dipped 
in clay-water are rammed in — nailing — with the sand, as 
seen in Fig. 70. The upper half-pattern is then put on 
the lower half and weighted, the sand rammed to the 
middle plane D of its flange. Fig. 69, the joint sleeked 
over, parting sand strewn thereon, and the cope E put 
on, liftered and rammed. The flasks are then parted, the 
pattern withdrawn, the mould cleaned, blackened, cored, 



PRINCIPLES OF GREEN SAND MOULDING 143 

and closed, the pouring basin F made, and all is ready 
for casting, as in Fig. 69. 

Figs. 71 and 72 show in vertical section and in plan 
respectively the mould through a column which has been 
made by turning over. Here the top and bottom boxes 
are alike. The sand in the top is liftered, the mould 








M 



Fm. 71. 




(f o 



^:sl'J^ 




"XsT 



Fig. 72. 
A Column Moulded by Turning over. 



being long, is poured from both ends simultaneously, and 
strain is relieved by risers or flow-off gates placed about 
the central portions of the mould. Chaplets will be 
noticed by which the core is maintained centrally in the 
middle part away from the core prints. 

These, in bare outline, are the general processes of 
bedding in, and of turning over. I have purposely, in 
order to avoid confusing the mind of the student, omitted 



144 PRACTICAL IRON FOUNDING 

to explain certain important items essential to safe 
moulding, which we must now consider. 

Venting. — Vents are variously made, according to cir- 
cumstances. When a pattern is being rammed, the sand 
by which it is surrounded is pierced with innumerable 
small vent-holes of about ^ in. in diameter, more or less. 
These do not properly come quite close, but only to 
within ^ in. or \ in. of the pattern. When vent-holes 
come out on the actual mould surface, there is always 
risk of the metal entering the vents and choking them, 
and, by preventing the escape of air and gas, causing a 
waster casting. All the small vents are brought into 
larger ones, and the positions of the larger ones will 
depend on the nature of the mould. For instance, when 
a pattern is bedded in, and the area of the mould is 
large, all the lower surface vents are carried directly 
downwards into a large porous reservoir of cinders, 
clinkers, or coke — hence termed a coke-hed or cinder-bed. 
In this, layers of hay alternate with layers of cinders, 
and the whole is covered with a final stratum of hay. 
This bed is laid at a depth of 10 in. or 12 in. beneath 
the lower face of the mould, and has a total thickness, 
including cinders and hay, of 10 in. or 12 in. Into this 
the vents are carried, and from it the air is led away, and 
escapes through vent-pipes. Fig. 88, p. 167, illustrates a 
mould having a cinder-bed and vent-pipes. The larger 
vent-holes are made with a vent-wire of ^ in. or f in. 
diameter, usually at an early stage of the bedding in of 
the pattern, or as soon as the general contour of the 
mould is obtained, and before the pattern is put back for 
final ramming up. But after the pattern is withdrawn, 
the vent openings, if not already closed by the bedding 
in, are filled up by the consolidation of the surface sand 



PRINCIPLES OF GREEN SAND MOULDING 145 

with the hands of the moulder, which invariably follows 
upon the withdrawal of a pattern that has been bedded 
in. By exerting gentle pressure with the fingers over the 
whole of the surface in detail, the moulder ascertains 
what sections are not sufficiently firm, and adds fresh 
sand in those parts, using the rammer for the purpose. 
At the same time he closes vent-holes which may yet 
remain open. On first thoughts it may seem strange to 
make vents and then close their openings, but the air 
and gas will force their way under the liquid pressure 
existing in the mould, through an inch or thereabouts of 
intervening sand, to the vents, while the metal itself 
will be unable to do so. 

Diagonal vents are brought from the sides of a mould 
into shallow channels or gutters which are cut in the 
sand, forming the joints of the mould, and are thus 
carried away at the box joints. The vents from the 
upper surface of a mould are brought off directly through 
the whole area of the upper surface of the cope sand. 
In Figs. 67 and 69, the upper surface vents are brought 
out over the tops of the copes A and E respectively, 
covering the whole area. The venting is therefore direct. 
Vents in the drag, in work which is turned over, are 
first made directly to the pattern face before turning 
over, and are then brought out at the joint which the 
under surface of the drag makes with the levelled bed of 
sand on which it rests. The necessary connection with 
the outside of the flasks is made by passing a long 
vent wire from the outside between those faces in all 
directions. The vents therefore in Figs. 65 and 67 pass 
from the lower faces of the mould perpendicularly through 
the drags B and B, and then out at right angles herewith, 
on a level with the sand floor upon which the drags rest. 

L 



146 PRACTICAL IRON FOUNDING 

The vents from the peripheries of these moiUds are 
brought out diagonally into gutters cut into the mould 
faces, and the air escapes through the joints of the 
flasks. 

Sand which is rammed hard will require more venting 
than loosel}" rammed sand. Free open sand will require 
less than close loam}^ sand. The red sands are so free 
and open that for many kinds of light work no venting 
is required at all, their natural porosity being sufficient 
to allow of the escape of the air. In heavy work the 
vents may be kept farther from the surface than on light 
work. The more moisture present in a mould the greater 
the quantit}^ of venting necessary. 

Eetention of Sand. — Another important matter in 
moulding is the artificial binding together and retention 
of large quantities of sand in their boxes. It is clear that 
the mere ramming of a large mass of sand in a flask, with 
no other support than that afforded by the sides, and the 
bars or stays, would not prevent the tumbling out of por- 
tions of that sand by concussion, or even by reason of its 
own weight. Numerous devices are therefore resorted to 
in order to bind or secure it, both during moulding and 
at the time of casting. These methods are roddinii, lifhr- 
ing, and sprigging, signif^^ing that rods, lifters, and sprigs 
or nails are used in different moulds, or in different por- 
tions of the same mould, as binding agents. 

Rodding. — This means that masses of sand which by 
reason of their large amount of overhang cannot be sup- 
ported and stayed by the bars of the flask, are sustained 
by means of iron rods. Thus, as a typical example, a 
mass of sand overhanging a flange will be supported by 
rods, the opposite ends of which are either sustained by 
the main body of sand in the mould, or upon a drawback 



PRINCIPLES OF GREEN SAND MOULDING 147 

plate, or on any ordinary cast iron ring or frame, such 
as those which are often used for lifting the middle sand 
in some kinds of bedded-in moulds. Kods are used also 
in turned over moulds, in the middle flasks, which are 
destitute of bars. The general mode of rodding and 
Uftering middle parts is shown in Fig. 87, p. 165, rods of 
square bar iron being placed across the flask and sup- 
ported by the ledge (see Fig. 31 B, p. 96) that runs 
round the inside face. The lifters depend from, and are 
supported upon these. Similar rods are seen in the 
middle part in Fig. 69, p. 141. 

Lifters. — These are bent rods made both in wrought 
and in cast iron, the size of cross section and length 
varying with the dimensions of the work. They may 
range from ] in. to J in. in diameter, and from 4 in. to 
24 in. in length. They rest upon the rods as in Fig. 87, 
p. 165, or are suspended from the box bars as in Fig. 92, 
p. 170, and are set and laid in all possible positions 
wherever sand requires support. In some few cases they 
are not themselves supported, but simply act as binders 
within the sand, their bent ends resisting the tendency 
to dislodgement of the sand in mass. But when practic- 
able they should be suspended from, or rest upon, rigid 
supports. Judgment is required even in the a^jparently 
simple matter of the putting in of lifters, since if im- 
properly supported, a tumble-out of the sand and lifters 
en masse will probably occur. 

Sprigging or nailing. — Common cut nails are employed 
for strengthening weak sections of sand which are too 
small to be sustained by lifters. Or the sprigs may be 
considered as auxiliary to lifters, strengthening in detail 
the sand the principal mass of which is carried by the 
lifters. In all work where there are small isolated bodies 



148 PRACTICAL IRON FOUNDING 

of sand, narrow weak edges, projections, etc., long nails 
are inserted in quantity to bind those to the main body. 
The nails are not only inserted at the time of moulding, 
but also after the pattern has been withdrawn. Should the 
mould crack or show signs of giving way, nails are thrust 
in to strengthen it, and to prevent risk of the sand 
becoming washed away by the rush of metal. In the 
economy of mending up, these nails are indispensable. 
An example of sprigging occurs in Fig. 70, p. 141. 

Mendhuj ujx — This is necessary in most cases except- 
ing those in which the patterns are made for standard 
use, regardless of expense, and those in which patterns 
are moulded by machine. The causes of moulds breaking 
down are numerous, as, for instance, badly made pat- 
terns destitute of taper, of rough construction, having 
overlapping joints in the wood of which they are com- 
posed; the leaving those pieces fast which ought properly 
to be loose, too soft or too hard ramming, imperfect 
rodding or nailing, insufficient or excessive rapping, 
uneven or jerky lifting. These are the principal causes 
of the fracturing of moulds. 

At the time of withdrawing, or delivery of a pattern, 
the joint edges of the sand are swahhed, in other words, 
they are just damped or moistened with the swab or 
water brush in order to render the sand around the 
edges of the pattern as coherent as possible. Then the 
pattern is rapped, that is, a pointed iron bar is inserted 
in a rapping plate let into the pattern, or otherwise into 
a hole bored into the pattern itself, and the bar is struck 
on all sides in succession with a hammer, so loosening 
the pattern from actual contact with the sand in its 
immediate proximity. A lifting screw, or else a spike, is 
then inserted, several screws or spikes being used in work 



PRINCIPLES OF GREEN SAND MOULDING 149 

of large dimensions, and the pattern is lifted gently, 
moderate rapping with wooden mallets on its surface and 
edges being continued the while. 

After the pattern has been removed, the mould is 
carefully overhauled to note the extent of the damage, 
if any, which it has sustained. If the lift has been very 
bad and the work is very intricate, it is better not to 
attempt mending up at all, but to ram the pattern over 
again. If the edges chiefly are broken, it is in some 
cases desirable, as, for instance, in moulds taken from 
loam patterns, to put the pattern into place again, and 
make good the sand around the edges, pressing it down 
with the trowel and increasing its coherence by means 
of sprigs and the use of the swab. If the damage is of 
quite a local character, that portion of the pattern cor- 
responding therewith can often be taken off and put back 
in the mould as a guide by which to mend up. 

In sections which are inherently weak, a stronger sand 
should be employed than that which is used for the 
general facing of the mould; core sand may in certain 
sections be used with advantage. In most broken parts 
it will be necessary, where the main pattern or portions 
of the pattern are not utilized for the purpose, to use 
mending 2ip pieces. These are strips of wood cut to the 
outlines, curved or otherwise, of the broken sections, and 
held against those sections while the broken sand is 
being repaired and made good. 

In green sand moulding there is a process termed skin 
drying, which is serviceable as a means of slightly stiff- 
ening an otherwise weak section or area of sand. It con- 
sists in partly drying the surface of the mould, not in 
the stove, but with devils or open cages containing burn- 
ing coke or charcoal. Or a red hot weight, or other mass 



150 PRACTICAL IRON FOUNDING 

of hot iron, is suspended in close proximity to the mould 
for the same purpose. This skin drying slightly stiffens 
and hardens the sand, enabling it the better to resist the 
pressure of metal. 

The mould is not finished at this stage. Its surface 
has to be protected with hlackeniur/ or blacking. When a 
mould is skin dried this is laid on before the drying is 
done. The use of blackening is similar to that of the 
coal dust in the sand, namely, as a protection against 
the fierce heat of the metal. But the coal dust being 
mixed in small proportions is scattered finely among the 
facing sand, \Yhile the blackening continuously covers 
the face of the mould. The blackening being made either 
of ground oak charcoal, or prepared from plumbago, is 
essentially carbon, and the immediate effect of contact 
of the molten metal therewith is the formation of a 
gaseous film of one or of both of the oxides of carbon. 
Thus smoothness of surface is preserved, because the 
metal is prevented from coming into actual contact with, 
and entering into the interstices of, the sand, and fusing 
its surface, with the production of a hard skin of silicate. 
The action is further assisted by the coal dust in the 
facing sand. Hence the reason why heavy castings re- 
quire a thicker coat of blackening, and a thicker stratum 
of facing sand, than lighter ones. 

Wet blacking is often used on moulds of large size, and 
on those which are to be skin-dried. This is blacking 
mixed with water, thickened with clay, and laid on wet 
with a brush. Blacking in its ordinary state is applied 
as powder and sleeked with a camel hair brush and 
trowel. 

Powing. — The methods oi pouriiig or rnnning a mould 
are varied. Much depends on this apparently simple 



PRINCIPLES OF GBEEN SASW MOULDING 151 

matter. But in truth there is nothing in moulders' work 
which is insignificant or unimportant. From first to last 
care in little, and to a casual observer, trivial things, 
has to be scrupulously exercised. A trifling neglect may, 
and often does, ruin the work of several hours, or of 
days. 

Since the conditions of liquid pressure exist in moulds, 
several things become self-evident. The pouring basin 
must be higher than the highest part of the mould. The 
liquid pressure on any given portion of the mould will be 
statically equivalent to head x area x sp. gr. of metal. 
The pressure on a mould of large area will in any case be 
very great, and must be resisted by equal and opposite 
forces. The area of the ingates must be sufficient to fill 
the mould before the metal has time to become chilled or 
pasty. Also there are other matters of a purely practi- 
cal character, which must be illustrated to be properly 
explained. 

Various methods of pouring are shown in Figs. 73 to 76, 
pp. 155-156. A mould may be poured direct from the top, 
or from the bottom, or from both top and bottom simul- 
taneously, or it may be poured from one side. Most 
moulds are poured from the top direct. Figs. 67, 69, p. 141. 
When they are of considerable depth, or when it is de- 
sirable that their surface or skin shall be clean and 
smooth, that is, not roughened or cut up by the action 
of the metal, they are run from the bottom or from the 
sides. For it is evident that metal rising quietly in a 
mould will not cause such damage to surfaces as that 
which, falling from a considerable height, strikes the 
sides in its descent, and beats heavily on the bottom of 
the mould. When it is necessary that metal shall be 
poured from the top into a deep mould, its cutting action 



152 PRACTICAL IRON FOUNDING 

is often diminished either by making the mould in dry 
sand, or by placing a piece of loam cake at the area 
where the beating action is most intense, or by inserting 
a number of flat-headed chaplet nails in close prox- 
imity at that area, and allowing the metal to fall upon 
them. 

As a general rule it may be stated that, unless good 
reasons exist for the contrary practice, moulds should be 
poured from the top. Iron falling upon liquid iron re- 
mains hotter and in greater agitation than iron rising 
slowly. The latter will carry up the scum and dirt which 
it gathers from the sides of a mould, allowing these 
foreign matters to lodge under projecting portions: but 
the metal falling from above cuts up the dirt and scurf, 
keeping them in such perpetual movement that they can 
scarcely effect a lodgement in the mould. Eunning from 
the bottom, the metal becomes chilled as it rises; but 
running from the top, the last iron poured is as hot as 
the first. When running from the top and the bottom at 
once, the first metal is led in at the bottom, and after a 
portion of the mould is filled, the top metal is intro- 
duced, fallmg upon metal. The dirt is thus cut up and 
the iron is kept hot until the mould is filled. No set 
rules can be laid down for the most suitable method of 
pouring, the matter is entirely one for the exercise of the 
moulder's judgement. 

Examples of the simplest forms of pouring basins and 
runners occur at p. 141. These are only adapted for the 
smallest moulds. For those of moderate and of large 
dimensions, the forms of the basins and the modes of 
running are modified. The shape of a typical pouring 
basin and runner is shown in Figs. 86 and 89, pp. 165 
and 169. Though a rough-looking affair, every detail is a 



PRINCIPLES OF GREEN SAND MOULDING 158 

matter of design. First there is a depression at 0. This 
receives the first inflow of the metal. If there were no 
such depression the metal on being poured from the ladle 
would flow at once into the mould, and as some slight 
adjustment of the ladle is necessary before it is ready for 
emptying a full stream, a few drops would be running 
in during the making of such adjustment. These would 
form cold shots in the casting. Also, the iron falling for 
a considerable time upon a bed of sand would cut it up, 
and wash portions into the mould. But the depression 
in the basin receives and retains the first few droppings 
of metal, and forms a shallow reservoir into which all 
the remaining metal falls as in a bath, preventing the 
cutting up of sand. Only when the depression is filled 
does the iron begin to flow off in a quiet stream into the 
mould. As soon as the depression is full the remaining 
metal is poured very rapidly into the basin until it is 
nearly level with the brim, and is kept filled until the 
mould is quite full. This is necessary in order to prevent 
any dirt or scurf which may happen to pass the skimmer 
from entering the mould with the metal. As long as the 
basin is full, the dirt floating on the surface will not be 
carried into the ingate. For a similar reason the surface 
area of the depressed portion is made sufficiently large. 
If it were small it would not hold much metal, and the 
scurf would be more likely to become sucked into the 
ingate. 

These pouring basins are made chiefly by hand. A 
small middle flask, or a frame only, is laid upon the 
cope, and swabbed with clay water, the runner pin put 
in place, the sand rammed with a pegging rammer, 
central portions dug out and then rounded and moulded 
to the proper form with the hands. All sharp corners 



154 PRACTICAL IRON FOUNDING 

which might become washed down by the rush or pres- 
sure of metal are scrupulously avoided. 

In spite of every precaution in the manner of pouring, 
particles of dirt which accumulate from the metal in the 
ladle, and from the sand in the basin, gain access to the 
mould. In castings which are not turned or planed, 
the slight contamination thus caused is not of import- 
ance ; but on turned or planed faces the slightest specks 
have an unsightly appearance, and in such w^ork various 
devices are made use of to obtain the cleanest faces 
possible. 

In steam and hydraulic cylinders, in pumps, and work 
of this class, a belt of head metal is cast on, into which 
the lighter matters rise, and this is subsequently turned 
off. On large flat upper surfaces an extra thickness of 
metal is allowed, to be planed off afterwards. Or, several 
risers are placed over the surface, and cut off. Lastly, 
the mode of running is modified, the metal being led in 
through a skimming chamber. This method is shown in 
Fig. 73. Here B is the ingate, and C, D, the runner. 
Eight in the course of the runner, which is purposely 
made of the indirect form shown in plan, there is a 
capacious chamber, Aj made by ramming up a ball or a 
disc in the mould. Over the chamber is a riser, E. As 
the metal obtains entry through the first portion, C, of 
the runner into the side of this chamber. A, it receives a 
rotary motion, as show^n by the arrows in plan view. The 
effect is to throw the heavy metal to the outer part of the 
sphere, leaving the scurf and inferior lighter metal at 
and about the centre. The outer metal passes into the 
mould by the ingate D, F, and the lighter matters float 
upwards into the riser E. This riser need not be added 
in very small moulds, the chamber in itself being sufti- 



PRINCIPLES OF GREEN SAND MOULDING 155 

ciently capacious; but in large moulds enough dirt will 
accumulate to fill it up to the brim. Fig. 74 is drawn to 
show by contrast with Fig. 73 the wrong way to make a 








■■■■ : ; ;.■•. : •• .• ^- • ', "i.;".*>7>.'.-' i'-:-v yy 



U'i'^'!'0 }: ::il^:.y^ 



iy 






VERTICAL SECTION. 




^■G— 



PLAN ON UNE CQ.. 



■■•fi-^^^^H??^^ 






Fig. 73. — Skimming Chamber. 




Fig. 74. — Incorrect Form of Skimming Chamber. 

skimming chamber. The runner entering and leaving 
the chamber in a straic/ht line, F, there is no rotary 
motion set up in the metal, and the chamber is useless. 
Sometimes a disc is used in the smaller moulds instead 



156 



PRACTICAL IBON FOUNDING 



of a ball. The workmen usually speak of the employ- 
ment of skimmmg chambers as runmug witli a hall, or 
ninning with a disc. Figs. 75 and 76 show the pouring of 
a cylinder cover through a disc, A. B is the ingate, C 
and D risers, C being over the disc and I) over the casting. 

[o^ 



rrf 



^ 




loT 



]s^ 



Y^ 



Fig. 75. 




Fig. *?id. 
Pouring a Cylinder Cover. 

The area of ingates should be in proportion to the size 
of the castings. Castings are light or heavy, thick or 
thin, machined or left rough, and all these points have to 
be considered in determining the sizes, positions, and 
character of runners. Thin and light castings should be 
poured from several thin runners, or from a spray. Fig. 



PRINCIPLES OF GREEN SAND MOULDING 157 

77 shows a thin runner stick of the type which is em- 
ployed for pouring thin pipes, etc. A heavy runner would 
draw a light casting, and probably cause fracture. The 
great length of runner is given to compensate for its nar- 
rowness, a large area being necessary for quick running 
of thin castings. Fig. 78 shows a pattern sjyray of run- 
ners, A, ready for ramming in situ, against pattern B, 
also used for the pouring of thin light castings, the total 
area of entry being large, while the spray itself is readily 



Fig. 77. — Runner Stick. 




Fig. 79. — Runner 
Pin. 



Fig. 78.— Spray. 



detachable after casting. Although heavy castings will 
require runners of large area, it is better, as far as prac- 
ticable, to employ several runners of moderate area 
rather than one or two of large size. Thus the runner 
pin shown in Fig. 79, which is the most common form, 
is not so good as the oblong ones in Figs. 80 to 82, being 
liable to cause a draw in its immediate vicinity. Runners 
of circular section are most often used, but those of flat 
and oblong section are in many, perhaps in most cases, 
preferable to the round ones, because they are more 



158 



PRACTICAL IRON FOUNDING 



easily and safely knocked oH' and chipped from the cast- 
ing. There must in any case he sufficient area, because a 
casting poured too slowly will probably show cold shuts, 
that is, imperfect union of the metal in some sections. A 
mould poured too rapidly will become unduly strained, 
and perhaps blown and scabbed. A light thin casting 
cannot be poured too rapidly or the metal be too hot; a 



^i:'^"» 



FT^ 



0---f- 







SICTIONON LINE.CG. 
Fig. 80. 



^ 









".r':vi:i;v>:v, '■■■'■■ ' 



Fig. 81 
Ingates and Kujnneks. 



heavy casting must be poured slowly, and the metal must 
be dcacL 

In cases where castings have to be machined the run- 
ners should be kept as far away as possible from the 
machined parts, as the metal is always dirty and spongy 
in the immediate vicinity of a runner. 

Figs. 80 to 82 illustrate two examples of running at the 
side of a mould. In each case .4 is the ingate and B the 



PRINCIPLES OF GEE EN SAND MOULDING 159 



runner. The pattern ingate, and the pattern runner are 
each rammed up in place, and the runner B in Fig. 80 
is then withdrawn into the mould in the direction of the 
arrow. In Fig. 82 the runner stick is drawn in the oppo- 
site direction, the sand being temporarily dug away be- 
hind for the purpose. Fig. 81 shows a loam cake, D, 
rammed in the mould, being better adapted than green 
sand in a heavy mould, to withstand the cutting action 
of the iron as it passes from A into B. 

Fig. 170, p. 251 illustrates the pouring of a large mould, 
suitable also for cylinders 
cast on end, through an an- 
nular pouring basin. The 
metal is poured in the de- 
pression L at the right 
hand, whence it overflows 
into the annular basin, and 
then falls through the 
runner passages disposed 
around the basin. After 
the mould is filled, any 
surplus metal runs off at M. 

Fig. 83 shows the external appearance of a mould after 
it has been poured. Here A^ A are the pouring basins for 
the ingates, B, B are the flow-off gates. The drawing 
shows the blue hydrogen flames all over the top and at 
the joint. 

Feeding. — A draw (see j)- 128) occurs because the sum 
total of shrinkage will be greatest where the greatest mass 
of metal is situated. Since the outer skin becomes chilled 
by contact with the sand and sets first, nearly all the 
later shrinkage goes on within the mass, and this 
naturally will produce a spongy and open casting. To 




'■|.v;'.->; •'■'*■■'■'&■;'.-' 



Fig. 82. — Ingate and 
Runner. 



i<;o 



PRACTICAL IRON FOUNDING 



Ijrevent this, the castmg is fed. In some cases the head 
east on to receive the scurf or sullage is made suffici- 
ently large and massive to do duty as a, feeder head. The 
mass of metal which it contains must then be sufficient 
not only to remain liquid until after the metal in the 
mould has set, hut also to exert considerable pressure 
upon the mould, feeding and consolidating at the same 
time. 

A feeder licad proper, however, is distinct from head 
metal, consisting of a basin or cup of metal somewhat 







Fig. 83. — Runners and Eisers. 



like a pouring basin, in fact a pouring basin is often 
utilized as a feeder head, as in Fig. 84. A feeder head 
must be placed directly over that particular portion, 
boss, lug, etc., the shrinkage of the mass in which it is in- 
tended to compensate, and its capacity must be so great 
that its metal shall remain fluid after that in the boss, 
lug, etc., has set. 

The feeding ox pumping is performed by getting a ] in. 
or f in. iron rod red hot in the molten metal in the ladle, 
and immediately the pouring has taken place the rod is 
inserted into the feeder head, Fig. 84, and a vertical up- 



PLATE V 




Fig. 187. — Pattern Plate and Moulds of Eailway Wheel. 
Lancashire and Yorkshire Railway 




Fig. 188. — A Pattern Plate 




See p. 268 I Faring j). 160 

Fig. 189. — McPhee Pattern Plates 



PBJNCIPLES OF GREEN SAND MOULDING 161 



and-down movement of the rod in the metal is com- 
menced, taking care not to touch the actual mould. The 
effect is to create an agitation or movement in the molten 
metal, and to keep a passage clear into the heavy and 
still molten central mass, in order that until it becomes 
actually set, fresh and ample supplies of hot metal shall 
enter from the feeder head to compensate for the loss 

due to interior shrinkage. In large 
masses it is necessary to supply 
added hot metal from a hand ladle 
to the feeder head. The pumping 
continues until the metal thickens 
and clings to the rod, when the 
latter is struck sharply with a bar 
of iron or hammer to effect the de- 
tachment of the clinging portions. 









Fig. 84. — Feeding. 



Fig. 85. — Flow-off Gtat 



'E. 



Finally the metal becomes so viscous that little more 
shrinkage will take place, and the feeding ceases. 

Risers. — In moulds of considerable area, risers ov floic- 
off gates are employed. Their function is mainly to relieve 
the cope of excessive strain, which in their absence 
would cause injury to the mould. There is an enormous 
pressure on a cope of several square feet in area, and 
though the flasks are made stiff and strong, and well 

M 



162 PRACTICAL IRON FOUNDING 

loaded, this pressure would, and often does, cause a 
thickening of the central portions of the castings to an 
extent of |^ in. or f in., due to the rising up or springing 
of the cope under pressure. Eisers relieve it partly, though 
not entirely, of pressure, but they also allow of free exit 
of the air and gas, which would otherwise be confined in 
the mould, and cause scabbing. The risers should pro- 
perly be kept closed with plugs of clay or sand until the 
mould is just upon the point of filling, when the plugs 
are instantly removed, and the pouring still continuing, 
the excess of metal is allowed to flow off quietly outside 
the flask. Fig. 85 shows one of these flow-off gates, the 
metal flowing away over the sloping bank of sand. 



CHAPTEE IX 

EXAMPLES OF GREEN SAND MOULDING 

We are now in a position to consider some examples of 
green sand moulding affording illustrations of the varied 
work which calls forth the best judgment of the jobbing 
moulder. Figs. 86 to 89 are illustrations of the mould 
made for an anvil block of four tons weight. It is an 
example of a deep and heavy mould. Though this is not 
a case of bedding-in, pure and simple, it illustrates the 
manner in which methods are modified in order to suit 
individual and special jobs. 

To begin, the top of the block must be sound, and that 
is therefore cast in the bottom. It is a deep mould, and 
there is a core, A, in the bottom for the anvil, there is 
also a great discrepancy in the dimensions of the smaller 
part of the block B, on which the anvil rests, and the 
base C, which is embedded in concrete. For these reasons 
the method of making the mould which is here shown 
was adopted. The whole of the stem B was made in flasks 
in dry sand. The method of supporting the sand in 
middle-part boxes by means of rods and lifters is shown 
in perspective in Fig. 87. The flask D was parted from E 
at the joint a — a, for convenience of placing the core A 
in position, but E, F, G were permanently cottared to- 
gether to form one middle. Blocks of wood were neces- 
sarily interposed between E and F, to allow of the entrance 
of the runner N' to the mould. This portion of the mould 

163 



164 PRACTICAL IRON FOUNDING 

was made, dried, cored, and finished first. Then a pit was 
dug in the foundry floor, a coke l)ed, IT, laid down at the 
proper depth, sand rammed and vented over it, and the 
box parts D, E, F, G all cottared together, were bedded 
down level thereon, their vents passing down to the coke 
bed H, and thence out through the vent pipes /, which 
are rough pieces of cast iron pipe of 3 in. or 4 in. dia- 
meter, reaching from the bed to the surface of the floor. 
The space encircling the flasks was then filled with sand, 
and flat-rammed level with the top edge L. The pattern 
being jointed at J and at K, as a matter of convenience, 
the portion from J to K was placed back in the mould, 
and the base C, dowelled by the face K, was laid in posi- 
tion for ramming, which ramming was continued to the 
top edge L. 

The cope M being perfectly plain was not rammed in 
place, but upon a levelled bed of hard sand, being liftered 
and vented all over its depth and area. A few lifters 
depending from their bars are shown in section at M', to 
illustrate the method of liftering. While the vents from 
the stem B go down into the coke bed H, those from the 
base C pass out through the cope M. 

The manner of pouring was as follows. There was one 
pouring basin, N, for running near the bottom, and one, 
0, for the main running at the top. The purpose of the 
runner N' is simply to fill the lower part of the mould, so 
that the metal falling from the top at 0' shall not cut up 
the sand, but fall into a pool of metal. A four ton ladle 
was used at O, and a one ton at N, thus allowing a ton 
for heads and basins. The pouring commenced at O, but 
merely to steady the ladle in position, and fill the hollow, 
0, of the basin. As soon as this was done, the ladle at 
N was poured, the plug P being kept in place until the 




b^^. 



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166 PRACTICAL IRON FOUNDING 

basin was nearly full, when P was removed, and the 
metal entered the mould. Immediately it had entered, 
the filling of pouring basin began, and when nearly 
level, its plugs, P', were removed, and the metal was run 
into the mould rapidly. The fact of its being filled was 
indicated by the flow-off at the risers Q, the plugs for 
which (not shown) were removed at that instant. After 
the cast, feeding was performed at the feeder head, U. 
The area of the runner N' was 3 in. x 1 in., that of 0\ 0\ 
6 in. X 1^ in. At the opening of each ingate, N" and 0", 
loam cakes were imbedded in the pouring basins to sus- 
tain the pressure of the metal, sand being liable in heavy 
casts to become cut up and washed away. The object 
of the flasks S, enclosing the ingate N", at the section 
where the ingate comes in very close proximity to the 
base, is to prevent a probable washing away of the inter- 
vening sand, T, which is a casualty to be guarded against. 
The pressure is in such cases enormous. 

To avoid confusion, no weights are shown on the cope. 
By calculation the pressure on the cope should be as 
follows : 

Area of surface C, Figs. 86 and 88, 5 ft. in. x 4 ft. 
6 in. Height from face of cope to level of pouring basin, 
about 18 in. Then 60 in. x 54 x 18 = 58320 in. 58320 in. x 
•263 = 15338 lb. 15338 lb. = 6 tons 18 cwt., statical load 
required, including cope. Actually 8 tons of weights were 
used. 

The flywheel mould shown in the succeeding figures 
is an example of a type of work by which the cost of 
pattern-making is much lessened. Instead of making a 
complete pattern, a process of sweeping up and of sec- 
tional moulding is adopted. It cannot properly be called 
bedding in, because there is no pattern, neither does it 








M 
o 
o 



o 
ft 
o 



GO 
00 

6 

M 



168 PH ACTIO AL lEON FOUNDING 

come under the head of turnmg over. It resembles m 
the mam bedding m, even though there is no complete 
pattern used, because the work is moulded in the floor, 
and a cope is the only flask used. The method is one 
which is often adopted in heavy work of this general 
type, such as rectangular bed plates, and circular bases, 
even when the internal portions happen to be somewhat 
intricate, intricate portions being readily formed by 
means of cores. 

A coke-bed should properly be laid down for this, un- 
less the rim happens to be narrow, in which case venting 
over the bottom, and diagonal venting therefrom to the 
mould joint will answer the purpose. In any case the 
cope is rammed before the lower face is touched, as 
follows : 

A bed of sand is rammed hard, and levelled with the 
foundry floor, and the striking board A, Fig. 90, is at- 
tached to the strap B and the striking bar C, the socket 
I) of which is bedded in the floor. By comparing the edge 
of this board with the pattern segment, Fig. 91, its coin- 
cidence with the edge of the segment is apparent. The 
board therefore strikes a reverse mould, upon which the 
cope, Fig. 92, is laid and rammed, a stratum of parting 
sand intervening. The reason why this method is adopted, 
instead of striking the cope direct, is that the precise 
ultimate position of the cope for casting is secured 
thereb}'. If the cope were struck separately, and put in 
place by measurement, it would be much more trouble- 
some to set it with accuracy than when it is rammed in 
place; for it is not a case of fitting of flasks with pins. 
The cope has to be laid upon the floor, and then the only 
setting which is available is that done with stakes of 
iron driven into sand, Fig. 97, D. Eeturning the cope to 



i' ■■■-■■''■?'■' A 




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170 



PRACTICAL IRON FOUNDING 



its original position by means of the stakes with which 
it was set for ramming, is simpler and far more accurate 
than striking it first and setting it afterwards. Before 










Fig. i)0. — Top Striking Boakd for Flywheel. 

the cope is rammed upon the bed several things have to 
be noted. 

Looking at the section through the ll\ wheel rim, Fig. 








Fig. 1)2.— Coi'E. 

do, it is clear that the formation of 
the face of the cope must take one of 
two directions. It must either coincide 
with the upper face, .1, of the rim, 
and with the horizontal central plane, 
B, of the bosses, or it must remain 
entirely continuous with the rim face, 
.1, .1'. The choice between the two methods is de- 
termined by the formation of the upper halves of the 
bosses, and of the prints which carry the arms. If the 



FiLi. lH.— Pattern 

Segment. 



EXAMPLES OF GREEN SAND MOULDING 171 

mould joint were shouldered down to be continuous 
with the centres, B, of the bosses, then Fig. 94 would 
show the joint face in section, and then it is evident 
that as many half bosses and half prints as there are 
bosses and arms in the wheel would have to be laid 
upon the reverse sand bed struck by the board A in Fig. 
96, and in precise coincidence with the positions which 
the lower halves of the bosses and prints are afterwards 
to occupy, and that the cope would be rammed over them. 
It would not be easy to set these bosses correctly. Nor 
is it advisable to lift the cope sand away from a deep 
shoulder, A, Fig. 94, such as that against which the 




Fig. 93.— Section Fig. 94. — Alteknative 

OF Kim. Jointing of Coj'e. 

bosses would have to abut. Hence the reason for the 
adoption of the method illustrated in these figures. 

The lower halves of the bosses within the rim are 
formed by ramming directly from the pattern segment, 
Fig. 91. The upper halves are made in cores, the out- 
lines of which are shown dotted in Fig. 93. In this case, 
to give sufficient sand in the core above the beading 
on the boss, it happens to be necessary to increase the 
height beyond that of the top face of the rim. This 
slightly complicates matters, because the thickness of the 
core C, Fig. 93, standing above that face, has to enter 
into a corresponding print in the cope. Hence six 
prints of thickness C, and of the same length and breadth 
as the core, have to be measured carefully into place on 
the reverse bed struck by the board A^ Fig. 90, in order 



172 



PRACTICAL IRON FOUNDING 



that their impressions may be imparted to the cope 
sand at the time of ramming the latter. These prints 
are shown in section, Fig. 92, jB, and in plan, Fig. 95. 
They are set by a circle corresponding in diameter with 
that of the inside of the rim, and their centre lines are 
made to coincide with the intended centre lines of the 
arms marked upon the bed. They are prevented from 



V'.;'- 




Fig. 95. — Top Prints. 



becoming shifted during the process of ramming, by means 
of common cut nails driven down alongside of them into 
the sand. In this position they are rammed and their 
impressions obtained in the cope. The cope is liftered, 
Fig. 92, rammed, and vented precisely as though it were 
above a pattern, and it is then lifted off, taken away, 
turned over, and any broken edges mended up. 

Then the second striking board B, Fig. 96, is bolted to 



EXAMPLES OF GREEN SAND MOULDING 173 

the strap at such a height that its joint edge A coincides 
with the joint edge E in Fig. 90. The lower edge C coin- 
cides with the lower face of the rim, so forming the hed 
upon which the pattern segment, Fig. 91, is to rest. The 
corner D coincides with the external diameter of the rim, 
as shown dotted; or it may, if preferred, be of a larger 
diameter. The edge of which D is the termination, is 
made diagonal, because if made perpendicular the sand 
would tumble down — being made as it is, the segment 
pattern, Fig. 91, rests upon the bed struck by C, and the 
sand is rammed both on the external and internal sweeped 



o o T m 




. 'm': ■';--.'l"'/''.' ^'.•.•. •■:■•.■-'.'-.■ :":V''^;.'' •;' ■•'■';;' "■.'/'I'Vi'-'y'. '." •:;' 

*'■ ■ r- 

Fig. 96. — Bottom Striking Board. 

faces of the segmental pattern. The position which the 
segment has to occupy in relation to the swept-up bed is 
shown by its dotted outline given in the figure. The 
edge Ef it will be seen, corresponds with the upper face 
of the rim. 

The bed is made as though for a bedded-in mould. 
The sand is rammed hard in the lower j)ortions and well 
vented, and the vents closed with the fingers. A more 
open stratum of about an inch in thickness is lightly 
rammed over this surface and consolidated with the 
fingers, the board being swept around several times 
until an evenly rammed, well- vented, and smooth bed 



IH 



PRACTICAL IRON FOUNDING 



is produced underneath those portions which will be oc- 
cupied with the rim, and to a little distance without and 
within the same. Then the board is removed and the 
pattern segment laid down for ramming. This segment, 
Fig. 91, has the same section as the rim. Two half 
bosses, A, A, are fastened upon it very exactly at one- 







=n 



Fig. 97. — Plan of Mould, 



sixth of the circumference. Prints Bj B occupy the 
positions of the complementary halves. Ample taper is 
given to these prints, as shown. The segment is laid in 
the position seen dotted in Fig. 96, and rammed. The 
circumferential position of the segment at each remove 
is governed by the bosses, the boss near one end being 
dropped into the impression just made by its fellow at 
the end opposite. The precise length of the segment 



EXAMPLES OF GREEN SAND MOULDING 175 

extending beyond the bosses is not of importance. It is 
not at all necessary to ram the sand over the whole of the 
internal area, but only sufficiently far inwards to afford 
a backing for the rim mould, and for the bosses and 
their prints. This is seen in Fig. 97. At, and near the 
centre also, a space must be left for the small flask 
containing the boss mould. 

We now leave the rim for awhile, to note the prepara- 




FiG. 98.— Boss Mould. 



tion of the boss. This is rammed from a complete pat- 
tern in a small flask by itself. Fig. 98 shows the joint 
face of the lower half of this flask in plan. As the arms, 
which are cast in, have to come through the flask joints, 
these joints are left open to an amount sufficient for that 
purpose, blocks of wood, A, being inserted at the corners 
at the time of ramming, to keep the flasks at the required 
distance apart. The sand therefore stands above the 
joint faces of the flasks in both top and bottom parts, 
reaching to the centre of the arms. This explains the 



17<; 



PEAGTICAL TRON FOUNnTNa 



reason of ilu^, Rl()])iiig joint iiulicatod by tlic sliading. 
The raniiiiiiig up is quite simple, and is done in dry 
sand. 

After tli(^ boss mould is dried, it is set in the centre of 
the rim mould, Fig. 1)7, its position l)eing checked both 
i-a.dia,lly and horizontally, the rule, straightedge, and 
spirit-level being used, and the print impressions for the 
arms in rim and boss are all brought in line. 

The corc^s which form the upper lialves of the bosses 
are made in the box, Fig. 1)9. 

The arms are formed of malleable iron bar cut off in 
suitable lengths, and either jagged, oi- fullered, l^\ig. 100, 




Emm 



Fi<;. 1>1).— Cork Box. 



I'm. 100. — Fuiii,i<;RiN(} of Ahm. 



near the ends, to render their liold more secure than it 
would be if left smooth. 

They are now set in their places, both in the boss and 
rim, Fig. 1)7, /I, A showing tlie relative positions of arms 
and mould at this precise stage. All being thus set in, 
the cores forming the top halves of the bosses are laid in 
their prints. Fig. 97, one, C, being shown in place over the 
arm />. Then the cope being returned to the position in 
which it was rammed, by means of the guidance afforded 
by the stakes, l^'ig. 1)7, V>, these cores are confined 
securely, their u[)per portions, of the thickness C in 
Fig. 9B, entering into the impressions formed by the 
prhits in Fig. 1)2, />, and in Fig. 95. This particular 
example illustrates a 7 ft. flywheel, of 11 cwt., and six 
tons of weights were used on the cope. The pouring 



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EXAMPLES OF GREEN SAND MOULDING 177 

took place at two basins, and the metal was fed at four 
risers. 

The easting of the boss must not be done at the same 
time as that of the rim. If it were, the boss being small 




Fig. 101. --Centre Cross Casting. 



would cool at once, and, setting firmly, oppose the 
inward shrinkage of the rim by setting up the resistance 
of the rigid arms thereto; and the consequence would 
be that, since shrinkage must occur somewhere, the rim 
would become fractured. In this case the rim was cast 

N 



178 



PRACTICAL IRON FOUNDING 



twenty- four hours before the boss, and when its shrinkage 
had very nearly ceased the boss was poured. It was 
both poured and fed through the ingate. 

The casting in Fig. 101 was moukled without a com- 
plete pattern, three of them being made by the methods 
to be described. It formed the base or pivot upon which 
the superstructure of a big crane revolved. Fig. 101 shows 
the easting in elevation and in plan. The central boss A, 
being large, 2 ft. in diameter by 4 ft. 8 in. long, would 
have been an expensive job to lag up in wood. It was 



rrw ^ 









Fici. 102. — Sweeping Board 
FOR Boss. 




Fig. 103. — Loam Mould 
FOR Boss. 



therefore struck up in loam and sunk into the floor pre- 
viously to the ramming up of the cross. Fig. 102 shows the 
board used for striking the boss, and Fig. lOo the loam 
mould of the same. The part A in Fig. 102 strikes the 
straight part 2 ft. in diameter, the part /> strikes the 
collar; the length of (' is equal to the length (', 4 ft. 
8 in. in Fig. 101, and J) strikes a print for the end 1> of 
the central core E. 

The loam mould of the boss is built up of bricks 
laid radially. One course is sufficient, because although 
the strain on the mould when pouring is great, the bricks 
are rammed tightly round with sand. "When the mould 



EXAMPLES OF GREEN SAND MOULDINa 179 

of the boss is struck and dried, it is set in its permanent 
position, and before it is rammed around, the top is 
levelled. A parallel straight-edge is placed across the 
face E and a level is tried upon it. The straight-edge is 
laid in different directions in turn, and adjustments of 
the mould are made, until it is horizontal. If this were 
not done carefully, the boss would be cast out of truth. 

Before commencing to ram the cross, coke beds have 
to be laid down underneath the horizontal iiat-plated 
portions of the pattern (see Tig. 108, p. 188;. Coke or 
cinders are laid down there to a depth of, say, 5 in. or 




Fig. 1U4. — Half Pattekn. 



6 in., and covered with an inch or two of hay. It is not 
necessary to lay these down beyond the area of the plates. 
Their purpose is to receive the vents that go down from 
the Hat webs. Vent pipes are brought up obliquely from 
the beds, one from each bed at the outer end. These 
details are seen in Fig. 108. 

The half pattern from which the cross is moulded is 
shown in plan in Fig. 104, the timber shading indicating 
how it is constructed. The vertical ribs are screwed upon 
the plated portion, the screws passing through the plate 
so that they can be removed when the pattern is rammed 
up. The strips that form the plate are halved together 



180 



PBACTICAL IBON FOUNDING 



next the boss. The pieces which form the broad feet 
are glued and screwed on separately, and their brackets 
also. The half boss is formed of two pieces fitted be- 
tween the vertical ribs. The top face of the boss on the 
pattern terminates with the line ,v — a- in Fig. 101, which 
is coincident with the top face of the loam mould. 

The coke bed having been laid down, sand is'^thrown 



<b 



<9 



: c 




Fig. 105. — Setting Pattern into Mould. 



loosely all over it with the shovel, up to about a suit- 
able level for bedding the pattern into. The latter will 
have to be tried in two or three times until it has a 
good bedding in the sand, and with enough sand around 
its edges to hold it securely in place. At this stage, and 
before the bulk of the ramming is done, it is levelled 
carefully and set centrally upon the loam mould of the 
boss. It is levelled by laying a parallel straight-edge A, 



EXAMPLF.Fi OF GEFFN HANT) MOULDTNG 181 

Fig. 105, across it in various directions in turn, and 
placing a level upon the straight-edge. According to 
the indications of the level, one portion of the pattern 
is beaten down and another raised up by tucking sand 
underneath, until, in whatever direction the straight- 
edge and level are placed, the level shows the horizontal 
truth of the pattern. 

The half pattern is set centrally by laying a straight- 
edge B along the centre of the loam mould C of the 
boss, and bringing the central joint edge of the half 
pattern up to the edge of the straight-edge. The half 
pattern is now ready to be completely rammed. 

Obviously, in a case like this the sand cannot be rammed 
underneath the fiat plate. The latter is therefore un- 
screwed from the vertical ribs at an early stage of the 
ramming, which is easily done, because all the screws 
which hold the two together are put in through the 
plate into the ribs. This pla.te is unscrewed as soon as 
sufficient sand has been rammed around the ribs and the 
boss, in order to prevent the possibility of their being 
moved out of place by further ramming. The ramming 
is then completed in detail up to the level of the under 
face of the plate, the sand being strickled off level with 
that, the top edges of the ribs furnishing the guides for 
the operation. Before the strickling off is done, the 
vents are carried down to the coke bed beneath, a long 
fV in. or -^ in. vent wire being used. These vents are 
pierced pretty thickly, say 1 in. apart, going from the 
top of the mould down to the cinders. These are carried 
all over the area covered by the plate, and some are 
taken down a little way outside the ribs. Then the sand 
is finally tried over with the fingers, the damaged faces 
made good, and the whole strickled over level with the 



182 



PRACTTCAL IRON FOUNDING 



tops of the ribs. Finallj^ the plate is screwed on in 
place, and the ramming is carried up to its edges and 
to its top face. As there is a good depth of sand, in 
consequence of the depth of the ribs, rods are driven 
down, goiiig well into the bed below to support the sand. 



^- 



O 




a 



a 



6> 



Fig. 106. — Setting Pattern for Second Portion 
OF Mould. 



At this stage it is most convenient to ram the cope. 
This is perfectly plain, so that it might be rammed on 
any levelled bed aw^ay from the pattern; but it is better 
to ram it over the half pattern, because the cope can be 
returned into its position, guided by the stakes, with the 
top print impression central. To ram the cope in position, 



iv 



EXA3fPLES OF GBEEN SANB MOULDING 183 

it is necessary to fill with sand all the area not occupied 

by the half pattern, for the temporary 

purpose of affording a perfectly level 

bed to ram on. This sand is strickled 

off level with the half pattern which 

has just been rammed, the top face of 

the pattern affording a suitable guide 

for the levelling. Parting sand may 

be strewn over the face so obtained ; 

but it is better to lay sheets of brown 

paper over a large surface of sand 

which has to be rammed on, because 

it does not yield so readily as the sand 

beneath the rammer, and the surface 

therefore comes out more free from 

inequalities. The cope is well liftered, 

and vented over the areas occupied by the cross. After 

it is taken off, and turned over, the surface of the 



m 



1?K}. 107.— Board 

FOR Striking 

Central Core. 




Fia. 108. — Vertical Section through Completed Mould. 



sand is tried with the fingers, and portions that happen 
to be too loosely rammed are consolidated, and the sur- 
face is properly smoothed, finished, and blackened. 



184 PRACTICAL IRON FOUNDING 

The other half of the mould is now made. The half 
pattern is withdrawn from the portion just rammed and 
turned around into its new position, the temporary sand 
on which the cope was rammed being mostly dug away 
and removed to receive the half pattern, which is set by 
the same methods as before. The joint face across the 
centre is set over the centre of the mould of the boss, 
and the top face of the plate is levelled in all directions. 
At the locality where the ribs come against the ribs already 
moulded, the moulded portion is filled in with pieces of 
wood to prevent the sand from being pushed into the 
mould. After this is done, the ramming, venting, and 
rodding proceed precisely as the same operations were 
performed on the first half of the mould. Fig. 106 shows 
the mould as it appears at this stage, one-half being 
finished, and the half pattern lying rammed in the other 
portion. 

The central core is struck against the board, Fig. 107, 
with a core bar, hay bands and loam. The core is stood 
in the bottom print in the pin mould, it enters the top 
print in the cope, and the core bar projects through the 
cope to bring off the vent from the core. The mould is 
poured at the central boss, and one riser or flow- oft' gate 
is brought up from the end of each arm. The mould, as 
thus completed, is shown in Fig. 108. 



CHAPTER X 

DRY SAND MOULDING 

Whether the metal is poured into green sand or dry sand 
does not affect the essential methods of moulding adopted, 
since the same processes of turning over, liftering, rod- 
ding, and sprigging are employed in each case. But the 
classes of work done hy each method, and the mixtures 
of sand used, are different. Heavy work, and that which 
is wanted specially sound and free from blow-holes, is 
cast in dry moulds. Strong mixtures of sand alone can 
l)e dried. 

A dried sand mould must be dnj. This may seem a 
needless truism, but the point is one of very great im- 
portance. Since the mould depends for its venting on its 
porosity, the presence of moisture even in small quantity 
implies that the vents are impeded. 

If green sand mixtures were dried in the stove, they 
would pulverize and fall to pieces. And the strong mix- 
tures also which are used for dried moulds, though hard 
and sufficiently firm to resist great pressure of metal, are 
very tender when edges are concerned. For this reason 
the joint edges of such moulds are always yi?i?ic(/, that is, 
their immediate faces are pressed down with the trowel 
while the mould is yet green, so that when the joints 
are brought together the edges remain slightly asunder, 
as in Fig. 109, A. A fin or thin film of metal of course forms 
here, but this is of no consequence; while, on the other 

185 



186 PRACTICAL TEON FOUNDING 

hand, a crushed joint edge with the consequent falHng 
of the sand into the mould would, if extensive, result in 
a waster casting. 

Another point to be noted in connection with dried 
sand moulds is, that they will l)ear harder ramming than 
those in green sand, since they become porous in drying. 
For the same reason, less venting with the wire is 
required. The very close nature of the sand demands 
that its venting be perfect, and it can only be properly 
vented by the drying out of the moisture, and the car- 
bonization and desiccation of the hay in the horse- 
manure. As long as steam, even in small 
:*'.-"'-/^ quantity, is seen coming from the mould, 
f^^yf pouring is unsafe, and the mould should 

'^J^^l properly be returned to the stove. But 

^>y;>v ^' steaming mould poured while warm, 
that is, soon after removal from the 
Fig. 109. stove, is less risky than one which is 
Finned Joint, allowed to become cold first. There is 
also this advantage in the use of dry 
sand, that less gas is generated than in moulds made 
in green sand. This is a consideration in large moulds 
involving a great deal of work, because the presence of 
gas in quantity is apt to cause blow-holes and scabs, 
and any arrangement by which its amount can be re- 
duced is a distinct advanta^^e. 

Dried sand moulds will also bear more swabbing than 
those made in green sand. Too much moisture in green 
sand is always a source of danger. But the swab may be 
used freely in dry sand, and this is often advantageous 
at the time of withdrawal of the pattern or of mend- 
ing up, and the heat of the drying stove removes the 
moisture. 



DRY SAND MOULDING 187 

As in green sand moulding, so in dry, stronger facing 
mixtures are used in the vicinity of the pattern than in 
the body of the mould. The floor sand, either alone or 
mixed with slight proportions of stronger sand, is used 
for mere box fiUing. The cost of dry sand moulding is in 
excess of that done in green sand because of the extra 
cost of coke for drying. But this depends partly upon 
the system of the shop. When drying is extensively em- 
ployed the percentage of expense is comparatively small, 
especially when the superiority of the castings and the 
lower ratio of wasters are taken into account. 

Mouldinf/ Cylinders. — In this work two cardinal mat- 
ters are the durability of wearing surfaces, and the 
elimination of injurious shrinkage strains. The first is 
got by the employment of a liner of harder metal than 
that which is used in the cylinder body: the second by 
avoiding much excess of metal in any one locality. Neg- 
lect of the first results in excessive and rapid wear of the 
bore, due to the friction of the piston and the hot steam; 
neglect of the second results in blow-holes, internal 
strains and possibly fracture. The simpler a casting can 
be made the better for the moulder, who cannot ensure a 
sound casting if big masses of metal are lumped in 
proximity to thin parts. And if the latter are those which 
have to be tooled, the most careful feeding from head 
metal will not ensure clean, sound surfaces. 

In carrying out the work of cylinder making, two im- 
portant details have to be considered. One is the ques- 
tion either of using a pattern, or of striking up the mould 
in loam; the other is whether to cast horizontally, or on 
end. Neither admits of an absolute decision, but must 
be settled by special conditions. In brief, the choice of 
the first method in work of medium size is generally de- 



188 PRACTICAL IRON FOUNDING 

termined less by dimensions than by numbers required 
off. For small castings, however, a pattern would almost 
invariably be made, even though one or two castings 
only should be required. Some saving even then might 
be effected by striking up the pattern body in loam, in- 
stead of building it in timber lagging, and then fitting 
the valve casings, flanges, etc., in wood, to the loam, and 
moulding then from that composite pattern, in green or 
in dry sand, exactly as in the case of a full timber 
pattern. In the largest work, loam moulding is invari- 
ably adopted. That is, the mould is swept round against 
its brick backings, and the valve seatings and small at- 
tachments are made as pattern parts in timber, to be 
embedded in the loam by measurement. 

The question of casting horizontally or vertically 
seldom arises except in the case of the smaller cylinders, 
which are moulded from full patterns. A goodly number 
of firms make their cylinders horizontally, and with 
satisfactory results. Many men think the vertical pour- 
ing, with head metal, the safer, and would prefer that to 
the other; although admitting that by using clean hot 
metal, and by extended experience, excellent results are 
obtained in the other way in shops which deal with 
cylinder work in large quantities. And, after all, the cost 
of turning moulds up on end and fixing cups, etc., for 
vertical pouring, does not amount to much, and it gets 
rid of all risk of open metal on the upper portion of the 
cylinder bore. Certainly it is much the safer plan in the 
average class of shop. 

The annexed figures represent a double cylinder made 
in dry sand, cast with circular guides for the crosshead, 
having a foot for bolting to a convenient base, and with 
steam-chests, all in one. It is a good example of rather 




M 






O 

w 

1-3 
PQ 

O 



190 PRACTICAL IRON FOUNDING 

elaborate coring-out. Figs. 110 to llo show views of the 
casting. Fig. 110, right hand, gives a plan view of the 
cylinder and guide, and a section through the same. 
Fig. Ill is a half cross section through the cylinders on 
the line A-B — that is, through the exhaust passages, 
and a half cross section through the cylinders on the 
line C-D — that is, through the steam inlet passages. 
Fig. 112 is a longitudinal elevation; Fig. 118 a half 
section through the guides on the line E-F in Fig. 110 ; G, 
Fig. 110 is the steampipe in plan; H, the exhaust ditto. 
We see at a glance that this can only properly mould 
in one way — and that is as in the plan view Fig. 110. There 
are several troublesome features about that method of 
moulding, but not nearly so many as there would be 
with any other method. We settle instinctively that it 
must part along the line I-J, Figs. 112 and 118; and a 
glance now at the lifts shows us that several coreboxes are 
absolutely essential. Thus, I-J representing the joint alike 
of the pattern and mould, the overhanging parts at K 
will not lift; hence they must be cored, or the overhang 
must be formed with loose strips, which in this case, at 
least, are not desirable. Then (see Figs. 110 and 111) the 
steamchests must evidently be cored, and their cores 
must carry those also for the various passages. The 
hollow space M beneath the foot in Fig. 118 would deliver 
very well, but cutting it out in the pattern would involve 
considerable trouble, and be rather weakening to the 
pattern itself, while it offers every facility for simple 
coring. So, not of necessity, but for convenience, we 
core that out. The cylinder bores and the guides are 
necessarily cored. The space N, Fig. Ill, between the 
pattern joint, and under the passages G to H, must also 
be cored. There is a space 0, Fig. 118, which reaches from 



DRY SAND MOULDING 



191 



the pattern and mould joint to the plate or web which 
connects the two crosshead guides, and this also must be 
cored. Being cast on end, 



KlJ 



1 



D 



3 



. -a 




i-H 
r— ( 

6 



the necessary head metal 
will be put at P, P. These 
considerations settle the 
essential methods of con- 
struction. 

To mould the cylinder, 
the half containing the 
steam and exhaust pass- 
ages is first rammed up in 
a mixture of dry sand, the 
joint face being laid on a 
joint board, and the drag 
or top part placed around 
the pattern. There is no- 
thing about the ramming 
of this that calls for any 
special comment. The sand 
is rammed hard in detail 
and vented, all its weak 
corners and angles are well 
strengthened with nails and 
rods, and the mass of over- 
lying sand is properly lif- 
tered. Then the drag is 
turned over, the other half 
pattern laid on, and the top 
rammed, the flasks parted, 

the mould cleaned, the joints tinned, and the boxes run 
into the stove to dry. But the real work — that which 
presents difficulty, or at least that which demands 



p 

O 

(^ 

m 

o 
P 



CO 
r-t 
I— I 

6 

M 



11)2 PRACTICAL IRON FOUNDING 

especial care — has yet to be done, and this will now be 
illustrated in detail : 

The two great requisites in cylinder work, after the 
usual and ordinary precautions common to all moulds, 
are the proper venting of the cores, the proper securing 
of the same, and the making of safe and sufficient 
provision for carrying off the air away from the mould. 
The making of the cores is accomplished precisely on the 
same lines as any ordinary dried cores, but since some 
of them are flimsy, rather more caution has to be exer- 
cised in their case. Taking the port cores first, there 
are two usual modes of venting — one with rods, the 
other with strings, — each of which is practised indiffer- 
ently, the latter being most suitable for the smallest cores 
of all. For the smallest curved passage cores, fine string 
soaked in tallow may be used, and when the cores are 
dried, the tallow melting away, leaves the string slack. 
When strings are used for cores of moderate size they 
are either drawn out while the core is green, or after it 
has been dried. When drawn out while green there is a 
tendency of the string to cut through the cores at the 
corners. But if rods are rammed up crosswise, as shown 
at rt, a, Fig. 114, which illustrates a section along a core 
in the plane of one of the strings, the strings can be 
pulled out without much risk. When the strings are 
greased and allowed to dry in the stove, their charred 
fragments can usually be blown out of the dried core 
with the bellows. The extreme end of the vent at A is 
filled up with sand to prevent the entry of the metal — all 
the air being brought away at the opposite end of the 
core, coming off, therefore, into the print impressions. 

When rods are used, there are corresponding numbers 
of holes bored in the corebox, as shown in Fig. 115, and 



PLATE VII 




EiG. 192. — The Darling and Sellers Light Machine 




See p. 283 [Facing p. 192 

Fig. 193. — Woolnough and Delmer Machine 



DRY SAND MOULDING 



193 



these rods are thrust through the holes mto the box, and 
the core is rammed around them, taking care to keep 
them central with the thickness. If they get much out 





Flg. 114. 



Fig. 115. 




Fig. 116. 




Fig. 117. 




Fig. 118. 
Passage Cores. 

of centre there is a danger of the metal bursting into 
the vents, and causing a blown casting. The figure 
shows the corebox with the rods in situ, in readiness for 
ramming. After the core is dried, at the corners oppo- 
site each rod, Fig. 116, a, a, a narrow groove is filed, 





194 PRACTICAL IRON FOUNDING 

going down to meet the terminations of the holes formed 
by the rods. A string is inserted a little way into one 
hole, and carried round the curve, and through the 
other hole at right angles with the first. Now the por- 
tion filed out is filled up again round the inserted string 
with core sand, and the string drawn out, thus leaving 
a clear passage round the curve. The continuity of the 
vents should always be tried with the bellows for security. 
In the smaller cores it is not usual to carry the vents 
right round — the air striking away readily from the 
short unvented portion. The extreme end of the vent is 
of course always filled up with a plug of sand. 

In addition to the rods for venting, a rod or rods have 
to be rammed in to stiffen the core and to furnish the 
means of its attachment or anchoring, a hook being 
formed on the core rod or rods for the purpose, as shown 
in Fig. 117, which illustrates a core cut through in the 
plane of a core iron. 

The steam and exhaust cores are made somewhat 
differently. The corebox parts in two, one-half of the 
exhaust box being shown in plan, etc., in Fig. 118. Each 
half is rammed up separately, and the two stuck to- 
gether. The shape of the stiffening wires is seen in plan, 
in full lines on the right-hand side, the core being sup- 
posed to be only partially rammed up there. The vent is 
cut out with the trowel in the joint, as shown in the 
left-hand side, which illustrates the half-core finished; 
so that when the halves are cemented together, a central, 
rudely circular vent traverses the whole length of the 
core. The appearances of the ends of the complete core 
when cemented are shown in side and end views. 

The steam-chests are cast with the cylinders, the 
covers then being plain plates. Hence the prints for the 



JDBY SAND MOULDING 



195 



port, and exhaust cores, are placed in the steam-chest 
corebox. Also, since it is an advantage to be able to drop 
the port cores down from the top rather than to thrust 
them into their prints horizontally, the prints are con- 
tinued up to the top, a, Fig. 119, and the cores stopped 
over when finally in place. 

Fig. 120 shows the core finished. The central portion 
is filled with ashes, and a few rods are placed about to 
stiffen the body. Since the exact distance between the 
port and exhaust cores where they pass out at the valve 
facing is important as affecting cut-off, yV in. is allowed 



'"n' B 







Fig. 119. Fig. 120. 

Steam Chest Box and Core. 



for machining along their edges. Hence the reason of 
the shoulders in the cores. Figs. 114 and 117, which are 
the reduced widths, giving the tooling allowance. Further, 
to avoid broken print edges and mending up, careful 
moulders often ram up strips of hoop iron against the 
sides of the prints, a, a, a, Fig. 120, which, when em- 
bedded in and forming a portion of the core, are an 
absolute and secure guide. An eye, or a couple of eyes, 
are rammed in the core for lifting it into place, and an 
eye projects from the back for securing it bodily against 
the side of the flask. 

The main core K in Fig. 110 may be made either in 
a box or from a board. If several castings have to be 



196 



PRACTICAL IRON FOUNDING 



made — say over three or four — a box pays for its first 
cost; if only one or two castings, then a board is cheaper. 
If a board is used, as in Fig. 121, it is evident that the 
cored-out openings in the sides of the guides (see Fig. 113) 
cannot be struck, but must be made with a corebox. 
The section of this box will then be that shown in Fig. 
122; and the cores may then be made separately from the 




Fig. 121. — Striking Board. 



main core, being rammed on a bedding of sand struck to 
the contour of the box; or else on a bottom board, and 
nailed to the main core after they are dried. Or, they 
can be rammed directly on the main core, as in Fig. 123, 




i!ii 




Fig. 122. 



Fig. 123. 



Guide Cores. 



after the main core has been wholly or partially dried, 
the surface being cut up a little with the trowel and 
moistened with clay water, and nails stuck in at intervals 
to assist adhesion. 

The section of the main core is shown at Fig. 123, a 
small bar being used to go through the narrow neck 
which carries the bush. This bar cannot be large, but 
must be as large as convenient. Thus, if the neck w^ere 



DRY SAND MOULDING 



197 



cored to 2 in. diameter, the bar raight be IJ in. to 
allow just a thin layer of tow between the bar and the 
loam. But the portions which form the cylinders and 
the guides being much larger, the If in. bar must either 
be wedged into two larger bars — one at each end — or the 
increased size must be covered with core plates and hay 
bands. The first plan is not desirable in this case, through 
lack of rigidity, so the second is to be preferred. The 
section of this core, then struck on such a small bar, and 
taken through a layer of hay bands, is that represented 
in Fig. 123. 

When a corebox is used, a half-box will sufitice, by 

A 





A 

Fig. 124. Fig. 125. 

Half Box and Core. 

making two half-cores, and cementing them together. 
Each half is stiffened with rods, and a vent passage is 
cut through the joint. Fig. 124 shows a section through 
the half-corebox, taken through the centre of one of the 
guides, and Fig. 125 is a section through the finished core 
in the same position, A being the rods. These, of course, 
are not straight, since they have to pass through the 
narrow neck, but are bent beyond the neck to occupy the 
positions in the large diameter shown at A. 

The remaining cores call for no comment, their con- 
struction being quite apparent from the figures. 

We now suppose that the mould is comj)leted, dried, 
and ready for coring up. Before the cores are blackened, 



198 



PRACTICAL IRON FOUNDING 



they are all tried in place to see that they fit properly 
and leave the pro^Der amount of metal everywhere. Then 



CJ 




^^ 











Fig. 126. — Mould Cored up. 



they are blackened, put back in the stove for a few hours, 
or for a night, and are ready to go finally into place. 
Even more care has to be exercised in this particular with 
cylinders than with work of ordinary character, when 



DRY SAND MOULDING 



199 



the cylinders are not cast in the position in which they 
are cored, but vertically, when any insecure fixing will 
make itself manifest, to the great grief of the luckless 
moulder when he comes to his work on the following 
morning. 

In the first place, then, that portion which was first 




Fig. 127. 




Fig. 128. 
Mould Cored up. 



rammed, the bottom part— though actually the cylinders 
are cast vertically, — is laid on blocking or any convenient 
support, joint face upwards. Then the steam-chest cores 
are laid in their print impressions — see Fig. 126 {A, A), 
which gives a plan view of the mould, representing it as 
it appears at certain stages of the work; and Figs. 127 and 
128 (A, A), which are sectional views across the mould 



200 PRACTICAL IRON FOUNDING 

through the centre of the steam passage cores F, and ex- 
haust cores G, respectively. 

The vents from the cores A, A are brought away 
through holes B m the sides of the box part; a channel 
also, shown in Fig. 128, being cut in the sand from these 
holes to the back of the cores, w4iich cores may be 
fastened with or without screw bolts. If they were 
heavy, and their overhang very considerable, they 
should properly have been attached with a screw bolt, 
passing from an eye in the core through a hole in the 
box side, as shown at C, Fig. 126. But in this instance 
the core is well supported in its print impression, and 
is not of very large size. Hence a little dodge, such as 
that shown at D, D, Fig. 126 is sufficient to hold the core. 
A shallow groove is filed on each side of it, vertically, 
and grooves in the mould sides in corresponding posi- 
tions; and while the core is held back, bedding against 
its print, this is filled up with damp core sand, which, 
when dried, becomes an interlocking key or dovetail, 
holding the core securely in place. Another simple way 
is that shown at Figs. 126 and 128 at E, where a loop of 
wire is slipped through the eye of the core, and carried 
out through a channel cut for it in the sand, and a short 
bit of rod is pushed through the loop and down into the 
body of sand, thus holding the core securely back in 
place. 

Afterwards, the steam and exhaust cores F and G, 
which (Figs. 126-128) connect their pipes with the two 
steam-chests, are placed in. These, when laid in, have to 
fit their bottom print impressions, and also the impres- 
sions in the steam-chest cores, and to allow the correct 
thicknesses in bottom H and sides J; which thicknesses 
will have been tested at the first trying-in of the cores, 



DRY SAND MOULDING 201 

both by measurement and by the use of clay thickness 
pieces in the bottom where direct measurement is not 
available. The vents from these cores are not brought 
into the steam-chest cores at all, but through the round 
prints J in Figs. 127 and 128. There is a difference in the 
way of fitting these to the steam-chest cores. The exhaust 
core, Figs. 126 and 128, G, fits the steam-chest through 
nearly the whole depth of the latter. But this is not the 
case in the steam-passage core, Figs. 126 and 127, F; 
for it enters the chest at one corner, the bottom corner 
as the mould lies (see Fig. 127), K. Hence it is necessary 
to make provision for its support. To trust to chaplet 
nails only when the mould has to be up-ended for casting 
is not safe. A ledge therefore is formed on core A, as 
shown at K, on which the steam-passage core rests. This 
may then be either stopped over with a small rectangular 
core L, as in Fig. 127 — left-hand — nailed on; or the box 
may be so formed as to continue core F to the top, and so 
stop itself off, as shown at M, on the right-hand side of 
the same figure. In either case the result is the same — 
the leaving a steam entry of width N into the steam-chest. 

Each core is secured in its bottom print by means of 
a wire carried from it through the box, and twisted fast 
round a bit of iron rod, Figs. 127 and 128, 0, 0. 

There is now the core which forms the inter-cylinder 
space, seen at N in the drawing of the actual casting. 
Fig. 111. This might deliver itself as part of the mould by 
leaving the portions of the steam and exhaust pipes which 
bridge across it, G and H, in Figs. 110 and 111 loose. It is 
better, however, to core it, and this is shown in Figs. 127 
and 128. The core P, therefore, is shown fitting in its 
print impression P^ in both views (Figs. 127 and 128), 
the print thickness P^ happening to coincide with the 



202 PRACTICAL IRON FOUNDING 

thickness of the metal in the steam and exhaust pipes. 
This shouldering of the print takes place beyond the 
pipes, hence the appearance of the core in Figs. 127 and 
128. The vent from this core is carried out at the back, 
in a line with 0, and beyond it, of course, in the figures. 
The main cores Q, Figs. 126 and 128, are next placed in 
their print impressions, one only being shown in Fig. 126 
to the right. The precautions to be observed here are to 
see that the cores do not sag in consequence of the narrow- 
ing of the diameter at the neck which forms the stuffing 
box, and that the thicknesses of metal are equal all 
round, the equal thicknesses being dependent first on 
the truth of the cores, and second on the concentricity 
of the prints with the pattern cylinders. Clay thickness 
pieces will be placed underneath the cores for this pur- 
pose, and measurement will be also taken at the sides. 
When the thicknesses are obtained, chaplets will be 
driven in to sustain the weight of the cores about the 
central portions, avoiding those parts which have to be 
bored. The proper position for the chaplet in this case is 
at Q\ Fig. 126, under the shouldered or stepped portion 
lying between the cylinder bore and the guide. 

Again, when ramming up cylinders the vents of which 
have to be brought away at the ends in the fashion to be 
noted immediately, it is necessary to cut away the sand in 
continuation of the print beyond the front end — that is, 
the space enclosed between the dotted lines E in Fig. 126 
— which sand is made good after the cores are finally set 
in place. Since the mould has to be up-ended for casting, 
there is just the slightest chance of the cores shifting 
downwards slightly, and a careful moulder will leave 
nothing to chance. Hence at this stage it is desirable to 
ram up two rods, or pieces of flat or round iron, against 



DRY SAND MOULDING 



203 



the core end, cutting away and letting it go down a little 
into the body of hard sand below, as shown at Fig. 126 in 
the space li. Or, if there is sufficient room above the 
vent, a small flat, square piece can be rammed in, and 
kept in place with a rod bearing at the other end against 
the inside of the flask, as shown at 8. The holes Q^ ^ in 
the centre of the cores, in Figs. 127 and 128, are the vents 
through which the air strikes away from these cores, and 
they pass completely through from end to end. 

If the box is specially con- 
structed for moulding cylin- 
ders of one particular size, 
it will be made with holes 
in its joint face opposite the 
air channels in the main 
cores, as shown at II\ H\ 
Fig. 126; and the air will 
then be taken directly away. 
But in cases where ordinary 
flasks are used, the air is 
readily taken off at the back, 
between the bars, in the 
manner shown in Fig. 129, 

which gives a part section through the corner of the box. 
Here ^ is a diagonal passage cut in the end of the core B, 
establishing a communication between the main channel 
in the core, and the vent passage to be formed between 
the bars, the sand passage being made by ramming up a 
piece of rope C in the end of the mould, from which the 
sand has been removed, as just now noted, thrusting 
first one end a little distance into the core vent, and 
bringing the free end outside the flask, as shown. After 
the sand has been rammed, the rope is drawn out, 




Fig. 129.— Vent Eope. 



204 PRACTICAL IRON FOUNDING 

leaving a free communication between the core and the 
outside. The newly-made sand is shown darker than 
the rest in the figure, and this is dried now with a 
l^iece of red-hot iron. 

The difference in the core sections Q in Figs. 127 and 
128 is given to show the different appearance which the 
cores would have in section if made in the two ways 
previously described. Fig. 128 illustrates the cores as 
rammed in a box, with the four stiffening irons in 
section. In Fig. 127 two sections of a struck up core are 
shown, that on the right hand being against the face of 
a coreplate, that on the left through the haybands, 
which come intermediately with the coreplates. 

Taking the port cores T, T in the figures, one fits 
against the cylinder bore, and one against the ring which 
forms the recess terminating the bore, and a correspond- 
ing difference for the lengths is made in the corebox. 
Unless the cores are very deep, they can be readily put 
in without disturbing either the steam-chest or the 
cylinder core, by simply sliding them round the body 
and down into their places. If they are very deep, as in 
some low-pressure cylinders of compound engines, this 
cannot be done, and then the prints in the steam-chest 
core must be made jj in. or -| in. too long, to allow the 
passage cores to i^ass the extra space, which is filled up 
with sand after they are in position. Fig. 130 shows a good 
plan to adopt in such cases as these, being an example 
taken from a double-ported compound cylinder, 14 in. 
bore, and having ports 9 in. wide. Each single port 
opening being narrow, the core would be weak and 
flimsy. Hence these weak sections are rendered rigid by 
connecting them together at the otherwise free ends 
with a continuation piece of core, fitting into the print, 



DRY SAND MOULDING 



205 



so that they can be handled without risk of fracture. 
The spaces A, A are necessary in order to be able to get 
the wide port cores in, and they are filled up afterwards 
with sand. 

The vents from the cores T, T are taken off into the 
steam-chest core, no vents passing into the cylinder core 
at all. Sometimes, though seldom, they are secured into 
the steam-chest core. But the chaplets, Fig. 12(3, U, and 
the claywash daubed around the print joint, and the 
sand by which they are stopped over, are usually quite 
sufficient to retain them in place. The core which is 




Fig. 130. — Steam Chest and 
Passage Cores. 




Fig. 131. — Yents. 



uppermost in the mould is grooved on the face which 
abuts against the body core, in order to allow the air to 
pass up freely at the time of casting. Fig. 131. 

There now remain the cores which form the foot of 
the casting underneath the guides. These are three in 
number, and are shown in Fig. 132, which gives a plan or 
face view of the opposite half of the mould to that shown 
in Fig. 126 ; and Fig. 133 is a sectional view of the same — 
showing, however, the central guide cores in dotted out- 
line, in order the better to illustrate the relative positions 
of the cores. The same reference letters are used in both 
figures, but the guide cores are entirely omitted from 



206 PRACTICAL IRON FOUNDING 

Fig. 132. Each of these cores ^, ^ is well guided by its 
print, at surfaces on the outside, end, and bottom; and B 
by a shallow print all round. They are all, therefore, 
screwed up with bolts passing through holes made 
temporarily through the sand between the bars, to the 
back of the flask, and there screwed against long flat 
washer plates bridging across the bars, as shown in 
Fig. 133. The flask is turned over in order that the holes 
may be filled in with sand, rammed around the bolts. 

The cores being of considerable bulk, have cinders 
rammed in them to collect the air; and the body of sand 
in the box outside of the cores A, A is also vented with 
cinders, into which the air from the cores is conveniently 
brought, and out through holes in the flask sides, or 
downwards between the bars to the back. The courses of 
the vents are indicated by the dotted lines at C, C, C. 
Core D, though shown in its position relatively to the 
dotted cylinder cores, is not actually fixed in this half of the 
flask at all; but after both the cylinder cores are finally 
set in place in Fig. 126, IJ occupies the position marked 
V, V in that figure between the guides, and is secured in 
place by means of two rods shown at T^, V, which pass 
up into two corresponding holes in the core T>, Fig. 133, of 
slightly larger diameter, which permits of sand being 
rammed around to lock the core fast. Chaplets, shown 
at E, Fig. 133, keep the cores at the proper distance apart 
as required for the thickness of metal in the foot. 

Very few chaplets are wanted about this cylinder. The 
outer corners of the port cores are assisted with chaplets, 
and the thicknesses of metal between the ports themselves 
are secured by two spring chaplets or by double-headed 
ones. Those at the outer corners of the ports have their 
stalks inserted in shallow grooves cut in the sand with the 



DBY SAND MOULDING 



207 



trowel, and are covered np and fixed with moist sand. It 
would often be desirable to secure the cores still further 







-.-E 



Fig. 132. 




Fig. 133. 
Mould Cored up. 



with chaplets abutting against the base of the cylinder, 
but the necessity for this should, when practicable, be 
prevented, because the metal becomes chilled round a 



208 PRACTICAL TRON FOUND TNG 

chaplet, and there is always more risk of a blow in its 
vicinity than elsewhere. In all places where cores have 
been stopped over, or chaplet stalks inserted, or any 
mending-up done, the damp sand must be dried before the 
closing of the mould, by placing red-hot blocks of iron 
over or against the made-up portions, and a little oil 
[)()urcd over and around tlicm will hissen the generation 
of gas. 

We now consider what provisions have to be made for 
casting. The mould has to be poured on end — cylinders 
and head metal uppermost. The runner i:^ shown in 

Fig. 126 at W; in gates at 
X, A', two or three of the latter 
to each cylinder, dependent 
on its size. A plan view of the 
runner is shown in Fig. 134, 
' ■ ' ■ . • ••• • ■ where A is the runner and 

Fig. 134 — Ingate and B,B are the ingates. These 
K-uNNERs. are cut out while the mould 

is green. At C, in the latter 
figure, the risers are shown, through which feeding takes 
place. All the vents are examined to see that they open 
out clear; the fastenings of the cores are all made sure 
of. If the main cores have been made in a box and 
cemented together with chiy-wash, there is just a fear 
lest the halves should slide one over the other on up- 
ending, unless they fit properly in the ends of their 
prints. It is scarcely possible to exercise too much care 
in all these minutia; before finally closing and up-ending 
the mould, because should anything shift it cannot be 
remedied after the metal is poured in. 

The flasks, well cottered or screwed together, are now 
lowered into a pit in the floor, of such a depth as to 




Hi 




DRY SAND MOULDING 209 

bring the top at a height convenient for pouring. A 
pouring basin and risers are formed in the usual way. 
Vent pipes are brought up from the cores A, B in 
Fig. 138, while the vents from the body cores come out at 
C, Fig. 129; and all down the open sides the vents from 
the mould surfaces come out. 

Head-metal. — The necessity for putting head-metal on 
castings which must, when machined, have perfectly 
clean faces, has often been a point at issue between the 
foreman moulder and his employer. Generally, a moulder 
considers head-metal indispensable in engine cylinders, 
hydraulic cylinders, and rams, while the employer grudges 
the cost of cutting off the head, and maybe thinks that 
it is a moulder's fad, especially when he learns that there 
are shops in which cylinders are cast without heads. 

There is much more in this than can be settled off 
hand. There is no doubt that, under some conditions, it 
is safe to cast without heads; but these conditions do not 
exist in jobbing-shops doing general work, and mixing 
metal at random for all the work of the day. In such 
shops, when it is desired to turn out good sound work, 
it is not safe to cast cylinders without head-metal, and 
the cost of sawing, or slotting, or turning off a head 
is but a trifle compared with that of a waster casting. In 
foundries in which cylinders are a speciality it is often 
the practice to dispense with heads; by mixing special 
brands of metal, pouring it hot and clean, and using flow- 
off gates freely, heads are not found requisite. Often, 
then, in the case of cylinders moulded, i.e., not bricked 
up, the practice is to mould and cast them horizontally 
instead of in a vertical position. 

The function of head-metal is essentially two-fold: It 
acts as a receptacle for all the dirt, scurf, air (which 



210 PRACTICAL IRON FOUNDING 

would otherwise be arrested on the face of the top flange), 
and it also becomes a feeder to supply hot metal to the 
shrinking casting. In a very minor degree it fulfils a 
third function — that of producing liquid pressure, which 
tends to consolidate the metal below; but, if that were 
all, the result could be more easily secured by increasing 
the height of the pouring basin than by massing a rela- 
tively shallow head of large area over the casting. In- 
creasing the depth of a head within reasonable limits 
increases the soundness of a casting; but that result 
follows much less from the increased hydrostatic pressure 
than it does from the function of the head as a feeder of 
hot metal. The latter function is so very important that 
it is usual to supplement it by the practice of mechanical 
feeding, with a rod through the runner, see p. 161, and 
two or three risers besides. 

This function, therefore, of mechanical feeding is 
actually the most important one which the head has to 
fulfil. The first-named, that of collecting dirt, sullage, 
and air is very important only when due care has not 
been taken to exclude the first two from the mould alto- 
gether. Many a head is cut off with scarcely a trace of 
dirt apparent, or an air-hole visible in it when broken up 
for remelting. A careful moulder and furnaceman will 
generally keep dirt out of the mould, so that, if this were 
all, the top flange of a cylinder would face up clean even 
though no head metal were cast on it. Hence the chief, 
and almost the only, function of head which is worth 
consideration is that of a feeder to the casting. It is to 
this, therefore, that we will give attention. 

It is well known that, when the metal in adjacent 
parts of a casting is very disproportioned, draws, or hollow 
and open spaces will occur in the heart of the heavier 



DRY SAND MOULDING 211 

metal, see p. 128. This is caused by the thinner metal 
cooling and setting before the heavier. Since the latter 
continues to shrink for some time after the former has 
congealed it becomes drawn away from the central parts, 
leaving cavities there; the nature and extent of these 
will depend on the relative disproportion of the masses 
and on the character of the metal itself. The greater 
the disproportion present, and the stiffer and stronger 
the iron, the greater will be the extent of the drawing. 
It may take the form of large open cavities, or it may 
consist of very coarse open crystallisation with minute 
rifts between small masses of crystals, or it may partake 
of both characters — holes and coarse crystallisation and 
rifts combined; when such drawing occurs it is a sure 
indication that there is disproportion in adjacent masses 
of metal. Draws, it must be remembered, are not to be 
confounded with blow-holes and general sponginess; 
which occur in castings regularly proportioned. Blow- 
holes are due to the entanglement of air in the metal 
when liquid, and occur chiefly in the upper portions of 
castings, while drawing may occur anywhere, and has no 
relation whatever to the pressure of air. The two are 
totally distinct in cause and in appearance. 

It is not easy to fix the most suitable amount of head- 
metal for a given job right off without experiment ; 
usually, however, previous castings of a similar character 
afford some guide, but every one must stand on its own 
merits. A difference in design necessitates a difference in 
head-metal; the more disproportionate the sections of a 
casting the heavier should the head-metal be. 

Since the head-metal becomes the dirt receptacle — 
the feeder for its casting, that determines its mass in 
relation to the casting : it must be large enough, but 



212 VEACTWAL TRON FOUNT)TNa 

there is no advantage in increasing its mass unduly. 
But if it is insufficient, some of the dirt, instead of passing 
up into the head, will biu-ome lodged against the face of 
the casting. If the niass of metal in an annular section 
of the head is considerably less than that in a corre- 
spondhig annular section of the body of the cylinder 
it will cool down before the cylinder cools, and will thus 
be unable to fuliil its function of a feeder of hot metal, 
viz., to I'lll up the cavities caused by shrinkage stresses. 
One sometimes set^s head-metal put on in this fashion; 
but it is of so little value that the casting would be as 
well, probably better, without it. 

The i)roper form for head-metal is shown in Eig. lliO, 
p. 1\)H, where its diameter is as large as that of the 
cylinder body, and where there is a good radius which 
facilitates the passage o( dii t upwards from the llange, 
and there is sul'licient height and mass in the head to 
cause it to remain hot after the body of the cylinder has 
ceased to remain liquid, and so the head becomes an 
efficient feeder as well as dirt collector. Another example 
occurs in Fig. 17ti> e, p. 251. 

The idea might suggest itself that the head would be 
more efficient if made as large as a cylinder llange, but 
the adoption of such a method would cause the whole 
flange to become drawn, or open-grained, due to the 
metal becoming drawn away from the interior portions 
towards the outside faces, causing then either holes, or 
coarse crystallisation, by either of which the llange would 
become weakened, and tlie nuiking of a steam-tight joint 
rendered difficult. The heads illustrated are fully efficient, 
practically no dirt can lodge on the portion of the llange 
uncovered with head, because during the movements of 
the molten metal any light matters which do hitch there 



DRY SAND MOULDING 213 

become moved again and l>uoyed up into the head round 
the curved edges. The practice of feeding or j^umjnmj, 
which is done through the head, see p. 161, also assists in 
such movements, besides fulfilling its main function of 
carrying down supplies of hot metal from the head into 
the shrinking jjody of the casting l)elow. 

The diameter of a head is easily settled: it is not so 
easy to settle its height, and no rule can be given. It 
often becomes necessary in standard work, in order to 
secure the best results, to increase the height of a head, 
so that this becomes a matter solely for judgment and 
experiment; speaking generally, heads of from 4 in. to 
in. deep are suita))le for cylinders from G in. to 12 in. 
bore; from 12 in. to 18 in. or 20 in. bore, the heads 
should be 8 in. or 9 in. deep. Over these sizes the heads 
may average a foot deep, there or thereabouts, an inch 
or two more or less in height being of little moment. I 
should say that heads of 10 in. or 12 in. deep are suffi- 
cient for any cylinders, no matter how large. Heads of 
15 in. to 10 in. deep are put on hydraulic cylinders, but 
then they have to stand very heavy pressures. For engine 
cylinders, the heights given represent good safe practice. 

Head-metal will not feed a casting properly if the 
casting is badly proportioned; if there are very thick and 
very thin parts adjacent, the metal in the thicker por- 
tions will inevitably become drawn and open. It has 
sometimes been necessary to enlarge the areas in certain 
localities in cylinder passages solely to reduce the amount 
of metal adjacent and so prevent drawing. Many draws 
are never seen until cylinders have leaked and been 
broken up; but they often show on the face of a flange, 
and may even run from the flange into the passage 
adjacent. If the best results are to be obtained from 



214 PRACTICAL TBON FOUNBTNG 

head, cylinders must be so proportioned that there shall 
be no great disparity in adjacent thicknesst^s of metal. 
Thus, lumps of metal massed in the vicinity of passages 
or llanges should always be lightened out; this is not a 
question at all of saving a bit of nu^tal, but possibly of 
saving a casting. 



CHAPTER XI 

CORES 

The term core, used in a general way at least, is almost 
eelf explanatory. Any central portion, or a portion re- 
moved from central parts, is a core. But in foundry 
work the term has several distinct meanings, defined by 
the prefixes, (jreen sand core, drij sand core, loam core, 
chilling core. 

The term (jreen sand core simply denotes the central 
portions of those moulds which are made directly from 
the pattern itself, without the aid of a separate core box. 
Thus, the central portion of a plain open rectangular 
frame, like the surface boxes used for hydrants in the 
streets, would yield a green sand core, because moulded 
from the pattern itself, and the sand employed would be 
of precisely the same character as that encircling the 
pattern, and would be connected therewith by rods, nails, 
or grids, and undergo no process of drying whatever. 
These portions, though termed cores (often termed cods 
also), do not come properly under the present heading. 
Metal cores for chilling the holes in the hubs or bosses 
of wheels may also be disregarded in this connection, and 
also those loam cores which are bricked up, see Chapter 
XII, so that all we have to consider in this chapter is 
the cores made in dry sand in core boxes, and loam cores 
which are struck-up or swept up on bars. 

Cores are required when (a) there would be extreme 

215 



216 PRACTICAL TEON FOUNDTNG 

difficulty in so constructing a pattern that an impres- 
sion could only be taken of the central portions b}^ 
making a large number of joints in pattern and mould ; 
{!>) when the central sand would be so weak that it would 
not retain its form and position against the rush and 
pressure of metal; (<) when the cutting out of the in- 
ternal portions of patterns would render them excessively 
weak as patterns; and (</) generall}^ when it would either 
be impossible or extremely difficult to make or put the 
mould together, or vent it without the aid of cores. Thus, 
if we take almost any pump clack box or valve box with 
seatings we could make a pattern precisely like the cast- 
ing, making as many joints as would be required to allow 
of drawing the parts separately from the mould. But we 
should then meet difficulty (a) and also (<*). But the sub- 
stitution of a simple core or cores enables us to make a 
strong pattern, and to employ one or two joints only, in- 
stead of several, in the mould. Or, if holes of small area, 
but of considerable length, are required in castings, green 
sand would not deliver freely from similar holes made in 
the pattern, but would become cracked and broken away, 
even if a considerable amount of taper were imparted; 
neither would they withstand the rush of metal. Then 
the conditions (/>) necessitate the use of dry hard cores. 
And no more familiar example of condition (</) could be 
given than that of any engine cylinder with its passages 
and feet, and often other attachments beside. 

It is clear that the same conditions must exist in cores 
as in the moulds themselves. The substance of cores 
must be stiffened with rods, grids, or nails, precisely on 
the same principles as moulds, though the conditions 
and details are somewhat different. Vents of sufficient 
area must be provided to carry off gas and air, and the 



CORES 217 

cores must be secured against the pressure of liquid metal. 
These are all points of fundamental importance, and we 
will consider them in detail. 

First, in regard to the stiffening of cores. In a plain 
round core made in a box, a rod of iron is rammed up 
with it, and this is the simplest plan. In crooked cores 




^Ztl^ 



Fig. 135.— Steam Fig. 136.— A Grii>. 

Passage Core. 

the rods are either bent, as in Fig. 135, which illustrates 
the passage core of an engine cylinder, or grids are 
formed of wires or rods fastened together with solder. In 
large cores, grids are always used, like Figs. 136 and 137, 
having nuts or eyes by which to lift them. These grids 
may be of any outline, being adapted to their cores. 



'nnnnnoi 
innnnnooni 
(nnDTinDcnnanni 
ID □ c c?o D n D c rro on dL. 
^jinnnnnnnj 

Fig. 137.— a Grid. 



Fig. 136 shows one of a sweeped outline adapted to a 
sweeped core. Fig. 137 one of triangular outline; Fig. 136 
has a nut. A, cast in to take the screw used for lifting, 
Fig. 137 has a couple of eyes cast in for the same purpose. 
These are usually cast in open sand, the moulder using 
a standard pattern grid, having excess of length, and 
stopping it off to length and outline required. In large 



218 PRACTICAL IRON FOUNDING 

and intricate work several distinct grids may be bolted 
together, the bolts being so placed that they may be 
readily taken out after the casting is made, through open- 
ings in the cored out sides of the casting itself. 

Fig. 138 shows a grid used for a pipe core made in a 
core box, a grid being used in each half core. Similar grids, 
curved, are used for bend pipes of large diameter, the 
longitudinal portion stiffening the core, and the offsets or 
prongs giving local support to the sand. Stiffeners and 
grids of this kind are used both for cores rammed in core 
boxes, and for those strickled up on plates. But there is 
a large class of cores which are not made in boxes, but 
struck up on revolving bars. The bars then act as stiff- 

I I I I I I I I 

Pig. 138.— Pipe Grid. 

eners longitudinally, and the core is made in loam, the 
adhesion of which to the bar is assisted by the use of 
hay bands or hay ropes, twisted and wound around the 
bar. When cores are very large the bar is not increased 
directly in proportion, except for certain standard work, 
but is selected simply with a view to sufficient stiffness, 
and the size of the core is increased by the addition of 
hay bands and loam alternating with each other, and 
sustained with core plates A, Figs. 139 and 140. In 
standard pipe and column work, collapsible core bars are 
used. 

There is thus a very wide range in the size and char- 
acter of the bars employed. The smaller ones are made 
of gas piping; for those over about 3 in. in diameter, 
cast iron cylinders are employed, and these may be 



CORES 



219 



either parallel or tapered, according to the character of 
the work. The bars are invariably hollow, and pierced 
with numerous small holes. Fig. 139, for the air vents, 
which pass from the encircling core through the holes to 
the interior of the bar, whence they find exit at the ends. 
The bars are turned next the ends, Fig. 139, B, to form 
journals, which revolve in vees on the cast iron trestles 
used for their support. A boy turns at a winch handle 



\: W.* !i^j ••• H*'1 W'« • •WW *•»*. 






B 



AAA 
Fig. 139. — Core Bar and Plates. 






m 







Fig. 140. — Section through Finished Core. 



inserted in one end of the bar, while the core maker 
winds on the hay bands, and daubs the loam. This is 
work requiring the exercise of judgment. If the bands 
are not pulled taut, and laid on close, and the loam 
well worked into the interstices, the core will sag, or 
become baggy, will be out of truth, and dry unequally 
in different parts, and portions of the loam may flake 
off after drying. A layer of rope is laid on first, and 
stiff loam well worked over and between it as the bar 



220 



PRACTICAL IRON FOUNDING 



revolves, then another layer of rope and more loam, Fig. 
140. The core is partially dried he fore putting on the final 
coat, which is thinner than that first applied. Fig. 141 
shows a section through a core bar A, hay bands B, 
and finishing coat of loam, C D indicates vent holes. 
When plates are employed, as in Figs. 139 and 140, they 
are cast as thin as possible, and pierced with holes, as 
shown, to permit of their ready fracture and withdrawal 
after casting. When very large, the various plates are, 

in addition to the usual 
fastening to the bars by 
means of wedges, united 
and stiffened with bolts 
passing through them all, 
the bolts being inserted 
when the final course of 
hay bands is being wound 
round, and the nuts are 
brought for convenience of 
withdrawal opposite suit- 
able vent holes in the ends 
of the casting. 




Fig. 141. — Section of Core 
AND Bar. 



These core bars when 
of small diameter are used for light work, and when 
large, mainly for jobbing work. In regular or repeti- 
tion work of large diameter, as in many pipes and 
columns, the cost of hay bands and of rigging up 
core plates would bear too great a proportion to the 
value of the castings. In standard pipe work therefore, 
and in other work of that character, the collapsihle bars 
are employed. These are only }r in. or 1 in. less in dia- 
meter than the finished cores which they carry, and are 
therefore necessarily made collapsible, that is, they are 



CORES 221 

so constructed as to fold, or fall inwards, and so deliver 
freely from the cored holes. Much ingenuity has been 
displayed in their design, and several forms are in use. 
The general jmnciple of their action is this: The shell is 
usually formed of three longitudinal segments of cast 
iron, two of which are hinged loosely upon the third or 
rigid piece. The movable segments are retained in their 
expanded condition during the making of the core, and 
pouring of the casting, by various devices, as by circular 
discs, or by wedge-shaped bars and links, adapted to 
similar fittings. By means of cottars, levers, and links, 
the movable segments are released, falling inwards after 
the casting is made. The body of the bar is pierced with 
vent holes. The outside of a collapsible bar is, like an 
ordinary bar, left rough, the better to ensure the ad- 
hesion of the loam, which is daubed on directly, without 
the intervention of hay bands. 

The vents of cores are variously contrived, and are of 
the first importance, since many a casting is ruined for 
want of proper venting and securing of the core vents. 

The simplest vent is that formed in a plain core by 
means of a rod of iron rammed therein, and withdrawn, 
leaving a round hole, into which the air and gas gen- 
erated within the core collects, and from which it finds 
exit through the prints. In large cores numerous rods 
will be rammed in, and withdrawn thus; and in addi- 
tion to these, a quantity of smaller vents will be made 
with the vent wire, as in making moulds. In curved 
cores (Figs. 142 and 143) a different method has to be 
adopted. Core strings or core rojjes have to be used, being 
common string or rope rammed up in the core, and either 
withdrawn while the core is yet green, or allowed to re- 
main while the core is being dried; which process of 



222 PRACTICAL IRON FOUNDING 

baking chars the string, and allows of its fragments 
being blown out with the bellows. The latter method 
is rather uncertain, so that the better plan is to with- 
draw the string, the core being green, in which case 
two bits of wire rammed in the core. Fig. 142, prevent 
the string from cutting the corners by its tendency to 
straighten under tension. An alternative plan which is 
often adopted is that shown in Fig. 143, where three 
straight rods are rammed up in the core, drawn out, and 
the core dried. Then the connection is made round the 
curve by filing, a string inserted, and daubed and covered 





Fig. 142. — Core String. Fig. 143.— Venting Rods 

IN Core. 

over with loam. This is then dried, and the string finally 
withdrawn. 

In the case of large cores the central portions are 
formed of cinders, to act as reservoirs for the air and 
gas, precisely as in the bulkier sections of green sand 
and dry sand moulds. A vent hole or holes of sufficient 
area is then made, connecting this body of cinders with 
the outer air. 

In cores struck on bars, the hay is porous, and con- 
ducts the air into the central core bar, which is in- 
variably made hollow and pierced with numerous holes 
for that purpose. But there is no venting done with 
the wire in struck-up cores, as there is with those 
made in boxes. The latter are pierced with vent holes 



CORES 223 

similarly to moulds, but the hay bands and loam are, 
when dried, sufficiently porous in themselves. 

Cores are fastened and their vents secured in several 
different ways. In most cases they are set in print im- 
pressions, but not invariably. If a core is large and 
heavy, prints are not necessary. Still, in the vast majority 
of cases they are employed. 

The forms of prints are various, depending on the 
position and mode of support required. Cores may rest 
in the bottom of a mould, or be carried in the top, or 
at the sides, or be bridged across from one portion to 
another. They may be carried by print impressions made 
in other cores. A core may be carried by one print only, 
or it may have several points of support. 

Generally the rule is this. A core laid in the bottom 
is sustained by the bottom print only, the exception 
occurring when the core is so long relatively to its area 
that a bottom print alone would not afford it sufficient 
steadiness of base. In that case a top print will be used, 
or chaplet nails, or perhaps both in combination. But if 
the core, though long, has a broad base sufficient to 
afibrd steadiness, than neither top print nor chaplet 
nails are required. A core carried at the side, if short 
relatively to its area, will need no other support than the 
side print. If long, it also must be supported by chaplet 
nails, or if it passes right across a mould, by a print on 
each side. Cores carried at the sides may be either sus- 
tained by prints of the same kind as those used in top 
and bottom, or in pocket or drop j^^'ints, dependent on cir- 
cumstances. Pocket prints are employed when the joint of 
the mould does not coincide with the centre of the hole. 
In such a case as Fig. 144, if a round print were used it 
would have to be skewered on loosely, and the core 



224 



PRACTICAL IRON FOUNDING 



thrust in afterwards, which in this case could not be 
done, the core being unable to pass down by A ; or the 
cope sand would have to be jointed down around the 
dotted line B, to the centre of the print, which in deep 
or in moderately deep lifts would be very inconvenient. 
Using a pocket, or ' drop print,' the lift takes place to 





Fig. 144. — Pocket Print. 



the cope joint C, leaving a clear open space into which 
to drop the core, which is then filled over with sand, a 
stopping over board, Fig. 145, A, cut to clip the core, 
being held against the mould face while the space, B, 
above the core is rammed with sand. The core is then 
permanently secured as though in a round print. 



FTTfr 




Fig. 145. — Stopping over. 

But core setting embraces very much besides this. It 
is not always sufficient in large cores to trust to the 
pressure of contiguous sand for security. There is an 
enormous liquid pressure in large moulds, and this 
would, in the absence of due precautions, force the cores 
bodily out of place in their central portions, even if well 
secured at the ends in their prints; or would carry them 



PLATE IX 





Sec p. -Jsi) 



Fig. 197. — Pridmore Ma^chines 




Sec p -im [Facing p. -I'li 

Fig. 201. — A Pridmore Machine, fitted with Steam 
Pump Pattern 



CORES 225 

away from their prints if simply laid therein. A pipe 
core, or a column core, for example, would be bent and 
curved upwards until it would nearly or quite touch the 
top of the mould. A flat core with metal over its top 
face, and having therefore open space between it and the 
cope sand, would be floated up by the metal, and cause 
a waster casting. Chaplet nails, chaplets, and stops are 
therefore employed to steady cores in their proper posi- 
tions. The forms and sizes of these vary with their posi- 
tion and function. Figs. 146 to 153 show chaplets in situ. 
In Fig. 146, B\ is a chaplet nail driven into a block of 
wood, A\ to afford breadth and steadiness of base in the 
yielding sand. The height of this nail is adjusted to the 
thickness, B, of metal required. Upon the flat head, C\ 
of the nail rests the core, C. Fig. 147 shows another 
chaplet made by riveting a bit of iron rod, B', into a 
flat plate, A\ and used for a heavier class of work than 
the common chaplet nail. Here A is the core the upward 
thrust of which is sustained by the flat, A\ of the chaplet, 
which passes through the cope sand, B, being supported 
either against the inside face of a flat bar of the flask, or 
a bar of iron, C, placed temporarily across, as shown, to 
fulfil the same purpose. D is the thickness of metal 
between the upper face of the core. A, and the lower face 
of the cope, B. Fig. 148 shows another chaplet which 
lies entirely between core and mould faces, and having 
a thickness equal to the thickness, A, of the metal. In 
large heavy moulds these chaplets will be of correspond- 
ingly large area, so that two or three stalks may be 
required to connect the plates, Fig. 149. In light 
w'ork not subject to much pressure, spring chaplets are 
used, consisting of pieces of hoop iron bent round. 
These are retained in place by their elasticity, and are 



226 



PBAGTIGAL IRON FOUNDING 



mostly used against vertical or nearly vertical faces, 

Fig. 150. 

Chaplets have their faces curved when they abut against 






'B ^C' B-B' 



'' ' - ^;^^ 



•?WV.. v ^^^ ^-^. - 




Fig. 140.— Ciiai'let. 



Fig. 1 17. — Chaplet. 



^•^^^^■^ Q ^ CD 




Fig. 148. Fig. 149.— Triple Fig. 150. 

Chaplet. Stud Chaplet. Spking Chaplet. 




JM4. 




:<->^\7S!0 i- 



Fig. 151.— Pipe 
Chaplet. 



Fig. 152.— Pipe 
Chaplet. 



Fig. 153. 
Stop. 



curved faces. Figs. 151, 152, show two such forms, modi- 
fications of Figs. 146, 147. The core rests upon the 
stud in Fig. 151, but in Fig. 152 the stud is introduced to 
resist the upward pressure of the core. Fig. 158 shows a 
stop employed when the mould is subject to very great 



CORES 227 

pressure. It is made of cast or wrought iron, and turned 
bright, or ground. 

The evil of stops and chaplets is their tendency to 
cause blow holes in their vicinity. Should they become 
rusty the mould is absolutely certain to blow very badly, 
owing to the formation of gaseous compounds from the 
rust. Chaplet nails are often tinned to prevent rust. 
With the same object wrought iron chaplets, made by 
the foundry smith, are heated to redness in the fire and 
brushed over with tar or oil. Oil is also poured around 
and over chaplets while in place to prevent formation 
of rust during the time intervening before casting, and 
to cause the iron to lie quietly on the cold metal. In all 
but the thinnest castings the chaplet stalks become more 
or less fused by the metal surrounding them. But the 
heads usually remain visible, and do not amalgamate 
properly. Hence chaplets should never, if it can be 
avoided, be placed against faces or parts which have to 
be bored or turned. 

It is not only necessary to fix and properly vent cores, 
but to secure the vents as well, that is, to see that 
adequate provision is made for the escape of the air and 
gas from the interior of the core to the outer atmosphere. 
The vent openings must be so secured that there shall 
be no chance of the entry of the molten metal into them. 
If it gets in, the gas will not come out, and the casting 
will blow, and become a waster. A chapter could well be 
entirely devoted to this subject of securing of vents, so 
important is it, and so many are the methods adopted to 
attain this end, but we must be content to note a few 
leading points bearing thereon. Thus, it is risky to bring 
core vents off against an abutting face simply, unless 
means are taken to prevent any possibility of the pres- 



228 PRACTICAL IRON FOUNDING 

sure of metal causing an opening between the faces to 
occur. There is less risk, however, in horizontal than in 
vertical faces, and of the two, a lower horizontal face stands 
less risk than an upper one, because the cope is liable 
to, and does usually, lift slightly. Where vents are carried 
dowai through the bottom, they are taken into a coke bed, 
as already explained, p. 164, and thence out through a 
vent pipe or pipes. When they are brought into the cope, 
they are usually carried into one or two large holes cut 
through the cope sand. 

But prints afford the best means of securing cores, 
because if any slight separation of the core and mould 
occurs under pressure, the metal cannot, if the core and 
print are mutually good-fitting, run between them into 
the vents. Properly the cores should be cemented into 
their prints by means of core sand, or of black wash. 
This is usually done only in the most important work. 
In most cases it is sufficient, after the core has been 
thrust into its print, to press and consolidate sand around 
and into the joint. 

When distinct cores meet each other in the mould, 
vents should onl}^ be carried from one into the other 
when they can be secured through a print impression, one 
thus being checked into the other. When the joint is 
only a butt joint, then the core vents must be filled with 
sand immediately against the abutting faces, and the air 
be brought away at the opposite ends, where the cores fit 
the print impressions of the mould itself. 

In the case of cores struck upon revolving core bars, 
the air, after being brought into the bars, is carried out 
at the ends. 

Cores are dried in stoves or ovens heated with coke 
fires or gas. The smaller cores are dried in ovens having 



CORES 



229 



a capacity of a few cubic feet only; for the larger ones, 
stoves of from 18 ft. to 24 ft. long, 10 ft. to 14 ft. wide, 
and 10 ft. to 12 ft. in height, are employed. These are 
built of brickwork, and furnished with folding or sliding 
doors. The cores are laid upon a core carriage, which is 




^ -a n 



.... . .. --..,',, z zzz 



Fig, 154. — Tuyere Casting. 

a low iron carriage running on tram rails, and provided 
with suitable supports for the ends of the core bars, and 
with flat plates for cores made in boxes, and those formed 
with strickles. A temperature of about 400° is suitable 




Fig. 155. — Pattern of Tuyere. 



for the drying of cores : excess of heat burns the hay, and 
makes the sand or loam rotten and friable. 

The illustrations show the pattern-work and moulding 
for a small tuyere, selected because it is an example of 
double coring. 

Fig. 154 shows the tuyere casting in longitudinal sec- 
tion, and the pattern- work and moulding are illustrated in 
subsequent Figs. Looking at Fig. 154 it is seen that there 



230 



PRACTICAL IBON FOUNDING 



are two cores entirely unconnected, A being that for tlie 
blast passage, B that for the water chamber. The tube 
containing^ is cast to the outer bod}^ at the fire end; at the 
other it is connected to the body with a shallow bridge of 
metal, C. In moulding this a plain pattern is used. Fig. 
155, having a print at each end, and two separate cores 
are employed for taking out the interior. As these cores 
must be maintained concentrically, provision is made for 
this in the manner shown in Figs. 156 and 157. 

Fig. 156 is a plan view of the core-box in the joint-face. 
As the core is absolutely symmetrical, one half-box only 




Fig. 156. — Core Box for Tuyere. 

is made. The main portion is cut through with planes 
to the bounding lines of the body core, and the ends 
are screwed on separately, as indicated by the direction 
of the grain of the timber. The large end of the core- 
box is extended to correspond with the core print .1 in 
Fig. 155, which insures the concentricity of the body core 
in the mould (see Fig. 157). The similar disposition of 
the water tube and its core is determined by cutting 
holes, one at each end of the core-box, by which the 
tube piece is centred and its core by the print B on the 
pattern, Fig. 155, and by the print K turned on the 
tube-piece in Fig. 156. The bridge-piece C, Fig. 154, 



GORES 



231 



which connects the tube to the body, is rebated into 
the tube-piece in Fig. 156, and drops into shallow re- 
cesses in the sides of the core-box. The flange IJ in 
Fig. 154, to which the blast-pipe is bolted, is seen should- 
ered over the tube-piece in Fig. 156. Everything, there- 
fore, is central, and nothing can become displaced during 
ramming of the core. 

The two half-cores made from the box in Fig. 156 are 
not cemented together. Each is vented separately, the 
vents being brought out through the print ends at A, 




Fig. 157. — Open Mould of Tuyere. 

Fig. 155. The main cores are carried at one end only in 
a print impression — at the end A. At the opposite end, 
chaplets are inserted to support them centrally. The 
middle core for the water passage is perfectly straight, 
and is lowered into its print impressions in core and 
mould in the bottom box. The top half-core and mould 
are lowered over it. 

The same principles which govern the construction of 
patterns must be regarded in the construction of core 
boxes. Thus, regard must be had to taper and such ar- 
rangements of loose pieces as permit of ready withdrawal, 
strength of parts, economy of material, and so forth. 



232 PRACTTCAL TBON FOUNDTNG 

Further, it is always best when practicable to avoid the 
turning over of heavy cores, which is apt to cause their 
fracture. In most cases it is quite as easy to make the 
box so that the core shall be rammed up just as it has to 
stand in the mould — that is, top side up — as in any other 
way. Especially is this precaution necessary when i^rids 
and eyes are in question, the eyes being required upper- 
most for lifting the cores by. The patternmaker should 
bear this in mind when maknig his boxes. 

There are many cores rammed in boxes which are sym- 
metrical; and in these cases a half-box suffices, and a 
considerable saving is effected in material and cost of 
work in the pattern shop. Take a core like that shown 
in Fig. 157 as typical of a numerous class in which both 
halves are precisely alike; hence two halves are rammed 
separately, the joint faces sleeked level and united either 
while green or dry. In such cases each half of the core 
requires its separate grid. Taking a core which is united 
while green one half is first rammed in the box, bedding 
in during the process the "grid " or " core iron"; and 
in cases where there are thin sections of sand, nails ai'e 
put in precisely as in the weak portions of moulds. The 
sand is made complete to the joint face, and then a 
vent channel, rudely semicircular in section, is cut with 
the trowel. If the core is of large size — or when small, 
if the sand is close — vents are driven from this channel 
radially to the inside faces of the box. But if the core is 
small and the sand is open, there is no need to do so. 
The half-core is now lifted out with the grid and laid 
with its convex face downwards upon a bed of soft 
moulding sand. The corresponding half-core is then 
similarly made, turned over, and pressed down on the 
joint face of the first, the moisture and slight pressure 



CORES 233 

causing adhesion. The union is frequently assisted by 
sticking nails upward in the joint and allowing them to 
enter at equal distances into both halves. When the 
cores are made in halves, and united after drying, they 
are stuck with a wash of clay- water or of "slurry" 
made of thin loam and water. When cores which are 
unsymmetrical, but of circular section, are made in 
complete boxes, they are, if of moderate or considerable 
length, rammed in halves and squeezed together with or 
without a thin wash of clay-water intervening. Such 
cores must be turned over and laid while green on a 
bed of soft moulding sand before being put into the 
stove to dry. 

A convenient mode of turning a core over without 
damaging it when a large number are required is to use 
a light frame of wood, or preferably of iron, which is 
placed upon a quantity of loose green sand thrown upon 
the finished core, thus confining the sand in place. The 
frame, core and half-box are turned bodily over, and the 
half-box, then uppermost, is lifted away, leaving the 
core resting upon the soft cushion of sand confined by 
the frame. It is very simple, and often saves the fracture 
of delicate cores. 



CHAPTER XII 

LOAM WORK 

The advantage of loam moulding consists in the facilities 
which it affords for making castings of the most massive 
character without incurring much expense for pattern 
making. The apparatus used is of the most simple de- 
scription, consisting of spindle, bar, and striking boards; 
the materials being loam, bricks, and cinders: with the 
aid of these the largest and heaviest castings are made. 

Loam work is a specialized branch, which all moulders 
have not had an opportunity of acquiring, hence its ex- 
clusiveness ; but it is not more intrinsically difficult 
than the other branches. I am inclined to think it easier 
of acquisition; but here, as in many other instances, the 
question is one of supply and demand, rather than of 
special difficulty. Also, large loam moulds are costly, and 
men are paid then for their care, as well as skill and 
special knowledge. The mould for a condenser, or for a 
large cylinder, will often occupy a couple or three men 
for nearly a month, hence the matter of two or three 
days' time, more or less, is of small account in com- 
parison with the soundness of the casting. 

The art of loam moulding, after the first principles are 
mastered, lies in the exercise of the inventive faculty, the 
ability to scheme the best methods, to elaborate the 
safest, and on the whole the cheapest tackle: to conceive 
the main plan, and to execute the lesser details with a 

234 



LOAM WORK 235 

clear head, guided by the lessons born of experience. 
Loam moulding is an art in itself, and a man who can 
midertake any job, large and small, devise, and make, and 
rig up his tackle, and produce uniformly safe results, 
need never swell the ranks of the unemployed — he is in- 
dispensable. 

It is a great advantage to a loam moulder to be able 
to read a drawing correctly. If he cannot do so, he has, 
in intricate work, to depend on the explanations of the 
pattern maker before he can set about his task, or even 
decide how to do it, or line out his centres. Some loam 
moulders are quite independent of the pattern maker in 
this respect, doing all the lining out themselves. 

A 




-/////W / 




Fig. 158. — Base for Engine Cylinder. 

So much may be said about loam work, so many differ- 
ent cases may arise in practice, that the best way will be 
to take some concrete and plain examples and make them 
the vehicle for remarks on loam moulding in general. 

The example selected in Fig. 158 is the base which 
forms the bottom cover of the cylinder of a condensing 
beam engine. The top face A, as the casting stands when 
in position, is moulded and cast downwards, to ensure 
soundness. 

The apparatus used is as follows: in Fig. 159, A is 
the strikiug bar, B its socket. The socket, of cast iron, 
is firmly embedded in the floor and levelled, its broad 
bracketed face maintaining it sufficiently steady. It is 



236 PRACTICAL IRON FOUNDING 

bored out to receive the turned tapered end of the bar, 
or it is cast around the turned tapered end, in either 
case making a close, yet working fit. The tapered end 
is long, so that as the bar revolves, its top end shall not 
diverge sensibly from the perpendicular. Over the bar 
slides freely the straj:) C, which is pinched at any required 
height with its set screw. To the strap is bolted the 
striJdng hoard or loam hoard D, the profile of the edges 
of which corresponds in the main, though not in all de- 
tails, with the sectional shape of the casting required. 
F is the loam _2j/rfA^' or building up plate, made of cast 
iron in open sand, without a pattern, by means of sweeps 
only. 

Fig. 159 represents an early stage of operations. The 
socket, B, is set in place, the loam plate, F, levelled 
roughly on blocking pieces, G, or other convenient sup- 
ports, the loam board, D, notched out to clear the boss 
of the strap, and bolted thereto. The breadth of the 
sides of the bar A is definite, being usually I4' in., 2 in., 
2| in., or 2^ in., so that the radius of the board I) is 
less than the radius of the casting by an amount equal 
to H, the radius of the bar. It is easy to see the coin- 
cidence of the board with the outside of the casting by 
comparing Figs. 158, 159, the only point of difference 
being the strip, /, which is screwed on temporarily to make 
a parting joint, J, for convenience, and the step or check, 
K, which makes the top or cope joint. The edge of the 
board is chamfered, as shown at L, to avoid dragging up 
and tearing out of the loam. It is evident that loam 
boards should be truly level in order to ensure the striking 
of a level mould. Hence the top edge should, in shallow 
moulds, be planed square with the end which abuts against 
the bar, and a level tried upon it, as shown at Z. 



Plan. 




v■.•':■rv^Av: >-*>'-'^*'''f" 



■■■-. '':;v-v— r '^■^ •^^*»T'7 



Fig. 159. — Loam Moulding. 



238 PBAGTIGAL IRON FOUNDING 

When moulds are deep, the bar is apt to sag at the top, 
and to cause the diameter to alter. For this reason, and 
partly also to check any error in the cutting of the 
board, diameter strips and calipers are used for measure- 
ment of the mould. Fig. 160 shows the strip used for 
testing the interior of a mould, being made to clip 
the bar; and Fig. 161 the wooden calipers for the ex- 
terior. Their purpose is so obvious that they require no 
explanation. 

A thin coating of stiff loam is first spread over plate F, 
Fig. 159, and upon this the bricks, M, M, are bedded. 
The bricking up is a vital matter, since the bricks must 




Fig. 160. — Diameter Fig. 161. — Wooden 

Strip. Calipers. 

bind one another by being made to break joint, just as in 
masonry. Since moulds are irregular, and bricks are 
pretty uniform in size, the value of the broken bricks 
from previous moulds is apparent. These should be util- 
ized as much as possible instead of breaking new bricks. 
It is not possible nor necessary to maintain such regu- 
larity as in masonry — the appearance of a bricked up 
mould is rather that of Fig. 159 (plan). In building up 
cylindrical work the general rule is to keep the broken 
bricks next the mould face, and the whole bricks as a 
backing. The broken bricks conduce to better venting 
than the whole ones would do. 

When a mould is over 18 in. or '24 in. in depth, a cast 



L0A3I WORK 239 

iron ring is built in at about every six courses, to assist 
in binding the bricks together. 

The joints of the bricks are not only wide apart, but 
large quantities of fine cinders are interspersed with the 
loam in the joints. These are introduced for the purpose 
of venting, which is a better and more certain method 
than venting with the wire, though the wire is sometimes 
used in some sections where the loam happens to be 
massed in quantity in a mould. There must be sufficient 
coarse loam intermixed with the ashes to bind the bricks 
together. The layers of brick M' and M" are then built 
up in like fashion, with loam and ashes intermixed. A 
space of about 1 in. is left between the bricks and the 
edge of the board, and about f in. of this is daubed well 
over with stiff coarse loam — coarse loam because it 
affords a better vent to the gases and air, than finer and 
therefore closer loam would do. The work is then left 
standing for a few hours in order that the loam may stiffen. 
Afterwards the final coat of loam, passed through a fine 
sieve, is struck on, and finished by the edge of the board. 
Several sweepings around of the board are necessary to 
impart the final smoothness to the surface; then the 
mould is put into the stove to be dried. At this stage 
therefore the mould is completed up to joint J, which 
coincides with the lower face of the flange B in Fig. 158, 
the mould being made, as just now remarked, to pour 
the casting upside down. 

Fig. 162 illustrates the next stage. A cast iron plate, 
Gy is made, a thin coating of loam swept over one face 
and dried. The flange space iV, already struck, as in 
Fig. 159, is filled up temporarily with moulding sand level 
with the joint J, and then the loamed face of G is turned 
over thereon, parting sand intervening The strip J, in 



240 PRACTICAL IRON FOUNDING 

Fig. 159, is unscrewed from the board, and the second 
stage of bricking uj) is done on plate G, Fig. 162. 

Sometimes ring plates are used similar to G, merely 
for the convenience of parting a mould which is too deep 
to go into the drying stove entire. The upper portion of 
the mould is then lifted off on its ring before being put 
into the stove, and is replaced after it has been dried. 
The ring is like G, but its function is different, G in 
Fig. 162 being necessary because the under face of flange 
N could not be struck at the same time as the lower portion 
of the mould in Fig. 159, without much difficulty, due to 
falling down of the loam. 

There are four ribs, C, Fig. 158, cast between the 
flanges. These are made by imbedding four pattern ribs, 
0, Fig. 162, in corresponding positions, and spaces are 
cast out of the plate, G, to receive these. Whenever ribs, 
facings, brackets, flanges, which cannot be struck, occur 
in loam moulds, patterns of these have to be made as in 
ordinary work. In some cases where the work is intricate 
this becomes a source of trouble to the moulder. In the 
first place it is not easy to set sectional portions of wood 
very accurately in yielding loam. Then the wood remains 
in the loam for several hours, more often for days, and 
is liable, by its distortion, to produce inaccuracy. Again, 
it is not so easy to secure a homogeneous face of loam 
by building bricks against wood as it is by striking loam 
upon bricks. The wood has to remain in the mould 
either until the loam has become stiffened or until after 
it has been baked in the stove. In either case the with- 
drawal of the wood tends to damage the mould — more 
when it is baked, because the loam then absorbs some of 
the oily matter from the wood. This makes mending up 
of the faces troublesome, the oily surface not taking 



PLATE X 




Fig. 203. — The Farwell Hand Portable Machine 




•^ee p. -J'JT i l-'iiri ,1,1 ji. ■J4(i 

Fig. 204. — Farwell Universal Machine 



Plan. 





G CZZZ 






e- - ■y_-^-_:3 



Fig. 162. — Loam Moulding. 



n 



242 PBACTICAL IRON FOUNDING 

kindly to the wet loam used in mending. In such cases 
the surfaces should be scraped before being mended. It 
is the usual practice to oil the surfaces of the woodwork 
hubedded in loam; but this only partially assists the 
stripping. The ribs in the illustration, though suggesting 
these remarks, are so plain that they would cause no 
trouble. It is in work of a more intricate character that 
trouble occurs. 

At P in Fig. 162 are bricks which are made of loam, 
moulded into the shape of bricks, and dried. These 
occupy the spaces between the ribs. Loam bricks, as they 
are termed, are frequently used in moulds of this char- 
acter wherever there are narrow spaces between flanges, 
or brackets, or ribs. One reason is, that if the shrinkage 
of the casting takes place against hard unyielding bricks, 
the iron is liable to fracture. If loam bricks are used, 
they crush and yield before the shrinking metal. They 
have, moreover, the additional advantage of forming a 
good medium for venting, and this is an important 
point. In intricate portions of moulds it is safer to use 
loam bricks and an extra thickness of loam vented with 
the wire, than to bring the common bricks very near the 
surface. A thin body of loam against common bricks is 
always liable to become detached, and to cause scabbing 
by reason of the bubbling of the metal thereon. 

Outside the loam bricks P, a layer of common bricks, 
(J, is built, and over this again another similar course 
(j'. The thickness of loam is daubed and swept over 
the faces of the bricks according to the profile of the 
board D. 

The cope, and the central core yet remain. A plate, 
Fi, Fig. 163, is cast, studded over with prods to hold the 
loam which is swept over its face, as shown — the check K 



Plan. 








'-' .•/'•'- 




• >■ V' ; .':; ; :.^ 






Fig. 163. — Loam Moulding. 



»i».»i-'V>,' — ■; 



244 PRACTICAL IRON FOUNDING 

being formed to correspond with the reverse check K in 
Fig. 162 — and allowed to set firmly. While it is setting, 
the plate // is partly loamed up on separate blocking. 
The future position of this plate is seen in Fig. 163; the 
arms >S', shown at T>, in Fig. 158, are laid in due posi- 
tion, and stiff loam is daubed around them, so that when 
this sets the arms are kept pretty rigidly in place. 
While the loam is setting, the work on plate R is con- 
tinued; courses of bricks, U, U, are built upon the bed 
which has been already struck wdth the board, the joints 
being vented with cinders, or with the wire. Coarse loam 
is daubed around the outside, and also on the top of the 
uppermost layer. Then the plate, //, is laid upon the top 
layer of loam, Fig. 163. The irons, V, are for the purpose 
of wedging up and securing the core and cope when 
finally in place. H, bedding firmly on the loam, the 
spaces between the ribs are filled in wdth loam bricks, 
U', and these, with the deep prods cast on the plate, 
together with the stiff loam daubed between them all, 
form, when dried, a solid mass which can be turned over 
with perfect safety for closing the mould. The block IF, 
which gives the metal around the termination of the 
bottom steam passage of the cylinder, E, in Fig. 158, is 
bedded in, and the whole surface is lastly swept up and 
finished with fine loam, >S'/S', and the whole dried bodily 
in the stove. 

The turning over of a body of bricks, etc., like that in 
Fig. 163, is only done in cases where the mass is not ex- 
cessive. In the example which we have selected there is no 
difficulty or risk involved in turning over. But in some 
heavy work it would be necessary to make a reverse 
mould, and to daub the loam upon that, standing thus in 
the position in which it is to stand when finished. A.lso 



Plan. 





Fig. 164. — Loam Moulding. 



246 PRACTICAL IRON FOUNDING 

where a reverse mould would not be suitable, the prm- 
ciple adopted m Fig, 162 is often employed, that, namely, 
of striking one portion of a mould upon another, using a 
parting ring, G, and parting sand. 

Loam, like dry sand, must be thoroughly dried, so 
that no steam issues therefrom. When dried, the mould 
is blackened with wet blacking, and, as soon as this is 
dry, the mould should be finally closed for casting. The 
checks K, in Figs. 162, 163, furnish an accurate means of 
joining the top and bottom portions of the mould. Holes 
cut at Y, Fig. 164, enable the moulder to see whether the 
coincidence of the joints is correct, and if not, where to 
file away the loam. 

Fig. 164 shows the mould closed in readiness to be placed 
in the casting pit. Similar reference letters will assist in 
the recognition of parts identical with those in the pre- 
vious figures, and the outline of the mould is also dotted. 
The eyes V receive the rods F', which are secured with 
the wedges V", thus securing the central core and cope 
in place. The top and bottom plates, R, F, are clamped 
together with the clamps Z\ Z\ which are wedged. 
Eunner pins are inserted at x, to keep the ingates clear 
during the time of closing, and of placing in the pit. 
Then the pouring basin. Fig. 164, X, and riser cups, X', are 
made, and all is ready for pouring. In cases where the 
mould is of considerable size the practice is to fill the 
central space of a bricked up core, as >S'aS', in Fig. 163, 
with cinders, previous to casting. If this precaution were 
not taken, the air filling the vacant space would rush 
out with explosive violence on the pouring of the metal. 
The cinders form a natural vent, to the exclusion of 
excess of air. 

Feeding is performed at the riser cups X\ and at the 



LOAM WORK 



247 



pouring basin X. Vents are brought away all over the 
surface of the cope, and also from the bottom, the latter 
through diagonal vent pipes. 

The mould is sunk into the floor, or pit, and sand 
rammed around it, in order to prevent risk of the liquid 





Fig. 165. — Soap Boiling Pan. 



pressure from forcing out the bricks composing the 
mould. For large work, therefore, special pits are built 
in the foundry floor. These, when permanent, are built 
up with cast iron plates, or rings. They are made of 




Fig. 166. — Fikst Stage in making Mould. 



depth and diameter most suitable for the special require- 
ments of the foundry. 

Fig. 165 illustrates a soap boiling pan, and Figs. 166 
to 170 show how the loam mould was made. It was cast 
bottom upwards. The hole in the bottom receives a dished 
or cup-shaped vessel (not shown) surrounded by a flange 



248 



PRACTICAL IRON FOUNDING 



which was bolted to the mner face of the tiange on the 
castmg, so formmg the bottom of the pan. 

First the outside was swept up, and then removed to 
allow of rigging up the board for sweeping the inner or 
cored portion. Fig. 166 shows the first stage in the work. 
Plate A, about 3 in. thick, is cast with prods and sup- 
ported on wood blocking, and then a level loam joint 
face a is swept on it with the board B which is bolted to 
a strap set on the central striking bar in the usual way. 




Fig. 107. — Mould Body swept up. 



The loamed joint a is dried, and then an outer ring of 
cast-iron, D, Fig. 167, which is first loamed over on the 
under side, dried and turned over — is jointed to it, and 
on this ring the courses of bricks, E, Fig. 167, are built up 
and a coat of loam swept on the interior by the board F, 
which is made as shown, and attached to the central bar 
with two straps. The board has a strip h screwed on it to 
prevent the loam from falling from the overhanging 
body on to the level bed which has been previously 
swept over the bottom plate. 

When this coat has set sufficiently, the ring D with 



LOAM WORK 



249 



its bricked mould is lifted away, hung b}^ its lugs in the 
crane slings, and is put in the oven to dry while the 
inner portion or core is being swept up. Fig. 108 shows 
the bricking up on the plate G, and the sweeping board 
H rigged up. To allow the metal to shrink in cooling 
without risk of fracture, four tiers of loam bricks are 
built up between the common bricks, 90" apart. These 
are broken out with a bar soon after the casting has set. 




Fig, 168. — Core swept up. 



and so leave the hard bricks free to yield before the 
shrinking casting without risk of fracture of the latter. 
The overhang of the board is stiffened, and prevented 
from wobbling and dragging by means of an iron strap J, 
attached as seen in Fig. 168. When finished, the bottom 
plate with its core is put bodily into the stove and 
dried, and afterwards the outside mould is put in posi- 
tion finally. 

Figs. 169 and 170 show the top of the mould, which is 



250 



PRACTICAL IRON FOUNDING 



a plain cope only. It is formed of a plate K exactly like 
the bottom plate A in Fig. 166, with prods, loamed, and 
swept level with the board B in Fig. 166 to make the 
joint face c in Fig. 169. Six holes are cast in the plate 
through which the ingates d pass, the pan being poured 
thus. A pouring basin in sand is rammed on top, through 
which the runners are filled. This is conveniently formed 
in the manner shown in Figs. 169 and 170. Two cast iron 
pit rings e, e, are selected of any approximate diameters 
suitable, and laid concentrically on the top plate, and 
the annular pouring basin is made up between them as 




Fig. 169. — Mould Completed. 



seen in section in Fig. 169, half-a-dozen runner sticks 
being set in, while the basin is being moulded by the 
rammer, and smoothed by the hands. This is preferable 
to allowing the metal to enter by one or by two ingates 
only at opposite sides, as it would have a tendency to 
chill in filling the mould. Entering hot at so many 
different places there is no risk of cold shuts or of im- 
perfect edges. 

It is better to conduct the metal through an exterior 
basin L than to pour it directly into the annular channel, 
which if attempted would probably result in the falling 
of driblets of metal into the mould, to become chilled 



LOAM WORK 



251 



before the ladle could be properly adjusted to pour the 
main volume. Pouring the metal into the basin L, exact 
adjustment of the ladle is effected, while the basin slowly 
fills, after which a steady volume being emptied into it, 
overflows into the annular basin, and through the in- 
gates d. The basin L is made within any moulding box 
part /of suitable size, prevented from shifting by an en- 




FiG. 170.— Plan of Mould, 



closing body of sand. Opposite it is the flow-off basin M. 
This is made of sand alone, supported by ramming in a 
few wetted bricks. 

The top and bottom plates K and A are secured during 
pouring by means of iron clamps N, seen in Fig. 170 
and to the right of Fig. 169, held fast with wedges. For 
casting, the mould is placed in a convenient pit 0, Figs. 
169 and 170. The interior of the core has been filled with 
cinders to receive the gases quietly, and prevent explosion. 



262 



PRACTICAL IRON FOUNDING 



These are conducted away through a central pipe. The 
outside is rammed around with sand to prevent displace- 
ment of the bricks by the liquid pressure. The outer air 
will come up through the sand which will be well vented 
vertically with the vent wire. 

Loam patterns. — These constitute another t3^pe of this 
branch of work, having a single point only in common 




jm 



±: 



o 



.Q_. 



^ 





Fig. 171. — Hydraulic Cylinder. 



with loam moulds — the material in which they are made. 
They are employed when the work is of a medium size — 
too small to be struck upon bricks, yet so large as to in- 
volve costly outlay for patterns in wood. They are struck 
up pretty much like cores on core bars, except that no 
venting is required, and the surface is protected and 
rendered hard with a coating of tar. In many cases, 
however, as when one casting only is required, the core 



LOAM WORK 253 

is struck first and vented in the usual way, and then a 
body of loam, representing the thickness of metal in the 
casting, is struck thereon, a coat of black wash interven- 
ing. The mould is then made and the thickness re- 
moved, the black wash acting as a parting, allowing of 
the ready peeling off of the thickness, and the core is 
placed in its mould. The boards used for striking are 
similar to those used for striking cores. 

The figures illustrate the manner in which the pattern 
for one of the lifting cylinders of a hydraulic crane can 
be made. They afford a good example of the economy of 
patternmaking in loam when the cylinder is large in 
diameter and of considerable length. In this case it is 
12 ft. long by 18 in. diameter. 

Fig. 171 shows the casting. The bracket for the bottom 
chain pulleys is bolted to the flange A, while the end B 
forms the stuffing box for the ram; and by means of 
the facing strips shown at the sides three cylinders are 
bolted to each other on one side, and to the cheeks 
which form the side members of the crane post on the 
other. 

This is not a loam pattern pure and simple, but one 
of a composite character, being partly of loam and partly 
of wood. It is clear that the more intricate and delicate 
portions of patterns cannot be formed so economically 
or strongly in loam as in wood, hence there are few 
patterns which are constructed entirely of loam, except 
those of the very simplest and most symmetrical types. 
Generally, as in this instance, the main body is of loam, 
and the small attachments are of wood. 

The loam body is made as follows : A common core-bar 
(Fig. 172, A) is used, and hay bands are wrapped around 
it, sufficient in number to make up the size of the body 



254 



PRACTICAL IRON FOUNDING 



required. There is no need to use plates in a case like 
this (such as are rigged up when sweeping cores), be- 
cause a bar sufficiently rigid in itself can be selected 
without further aid from plates. A plate must be used 
at each end, in order to afford support to the loam there. 
Hay bands and loam alone form the pattern body. The 
bands, especially the first layer or two, must be left 
rather open, and the loam worked into the openings, 
going down to the corebar, and becoming interlocked 
and held fast among the bands, so that there will be no 
risk of its flaking off afterwards. 

As in coremaking, the first application must be allowed 



rvrr:^^, 






■gSiivtf^^^ ' 









B r> 



i^ 



Fig. 172. — Loam Pattern of Cylinder. 



to become partially set before the final coat is put on, 
and the last coat of all must be thinner and finer than 
that used for the main body. Fig. 172 shows the pattern 
at this stage, .4 being the bar, B the body, C the head 
metal, and J), /) the prints. 

The mode of attachment of the wood fittings to a loam 
pattern is governed by the facilities which are afforded 
by the shape of the pattern itself. Loose fittings are apt 
to become rammed out of truth, since the same means 
are not available for the attachment of wood to loam as 
for wood to wood. Screws cannot be inserted, and nails, 
though used, afford but a flimsy fastening in the loam, 
and their principal use is to steady rather than to 



LOAM WORK 



255 



secure. Square-shouldered portions (Fig. 172, a) afford 
ample means of security when wood is fitted to loam, 
because where such a deep shoulder exists it gives a 
good bedding for a wood fitting without any fastening, 
and the latter is readily held against the shoulder by 
pressure of the hand while the first portions of sand are 
being rammed around it. A recess like that at h is more 
secure still. Often, however, there need be no better fit- 
ing than thatwhich a butt joint affords. Then the wood 
portion may be either set and kept in place by careful 
measurement, with rule, straightedge, or square; or in 








Fig. 173. 



Ficx. 174. 



Wood Fittings. 



some cases slight assistance can be derived from nails 
passing deeply into the loam, either through the wood 
or alongside of it. 

Fig. 173 shows the mode of attachment of the bottom 
flange A in Fig. 171 against the shoulder a in Fig. 172 
one-half the flange only being in place, a face view of the 
same half being given to the left. The flange is simply 
held against the square shoulder until sufficient sand has 
been tucked around to keep it in position. The facings 
and core prints are self-explanatory. 

Figs. 174 to 176 illustrate the fittings which go at the 
head B in Fig. 171. The flange B forms — along with the 
flanges C, C by which the cylinders are bolted together 



25() 



PRACTICAL IRON FOUNDING 



and to the post, the rihs cl, d stiffening these — together 
with sundry prints and phming strips — a single pattern 
piece which drops over the portion marked h, E, in Fig. 
172; the flange 7J in Figs. 174 and 175 dropping into h in 
Fig. 172, and the flat A' in Fig. 172 being filed to allow 
the width D in Fig. 17() to embrace it. In the absence of 
the flats, the facings C, C in Fig. 176 would have to be 
cut away to fit the circular body of loam, which would 
not be so conveniently done. 

The prints E, E are merely for lightening recesses. 





Wood Fittings. 

and the pocket or drop prints ^ <' are for the bolt holes. 
This entire piece is retained in the groove h in Fig. 172, 
and therefore requires no assistance or support when 
ramming. 

The appearance of the completed pattern is seen in 
Fig. 177, the view being taken looking down on it from 
above, so that the joints in the fittings do not show. 

The economy of making large loam patterns is well 
illustrated in this example, both in regard to time and 
material saved. Hay bands and loam do not cost so 
much as wood, nor does the striking up occupy so much 
time as the turning of timber. But the latter is never- 



■■a 

Ah 





K 

CO 

W 
H 

PQ 
w 

EH 



o 

6 

M 

2 [^ 



r .? 



LOAM WORK 



257 



theless cheaper when there are many castings required, 
even though the pattern should be large. The question 
is merely one of relative cost. In this case the pattern 
was of large dimensions, and only three castings were 
required. The storage room necessary for large wood 
patterns also has to be considered when deciding between 
timber and loam. 

Loam patterns which are swept up are necessp.rily un- 
jointed, which is a slight disadvantage, because they can- 
not be laid upon a bottom board, neither have they a flat 
central face from which to square up and mark off the 











'^■'■^ /; ■VNS" ^V>> "' \ iiJ IM^^^^^i!!^5M&33ii 







U/\e^.:fMr', t> vA a< 



Fig. 177. — Pattern Completed. 



positions of their attachments. Hence centre lines have 
to be obtained by rule, compasses, and straightedge, and 
most squaring up must be done from the outer surface 
of the body or by geometrical means. 

When moulding a solid pattern of this kind it is bedded 
in the sand of the floor and covered with a top part; or 
in a complete flask. If in the latter, the box part which 
is to come in the bottom is rammed over it. Then it is 
turned over and the top rammed on. Or, if cast in the 
floor, it will be bedded-in like any other pattern, and the 
top part rammed. In either case a longitudinal centre 
line is marked deeply down each side as a guide to the 
moulder for marking his parting joint by, and the edges 



258 PRACTICAL IRON FOUNDING 

of the flanges must be tried with parallel or winding 
strips before the ramming is completed, and if out of 
truth with each other must be corrected. 

Cylinders of this character are cast on end to ensure 
closeness of metal, since they have to stand very high 
pressures. The metal is poured at the top, and falls the 
entire depth; and though poured as " dead " as it is safe 
to run it, and the mould made of dry sand, the iron will 
cut up and burn into the bottom portion of the mould. 
The driving in of a number of flat-headed nails in close 
contiguity (Fig. 178), just level with the surface of the 





Fig. 178. — Nails in Fig. 179. — Strickling. 
Bottom of Mould. 

sand, and well oiling them, will prevent this cutting up 
and burning, by giving the metal a hard bed to fall on. 

Loam patterns of irregular outline are worked up with 
strickles, guidance to which is afforded by means of guide 
irons, or by striking plates. The principle is simple. 
Fig. 179 shows a strickle of half a pipe, working by means 
of a check against a guide iron. A, which is curved longi- 
tudinally to correspond with the required outline of the 
pipe. Fig. 180. The guide iron remains in the same posi- 
tion for both core and pattern, the concentricity of core 
and pattern being assured by the method of cutting the 
checks upon each strickle, the distance, B, being less in 
the pattern strickle than in the core strickle by an amount 
equal to the thickness of metal in the pipe to be cast. 
In making the core, the vents have to be carried from the 



LOAM WORK 



259 



outside to the central portion, and away at the ends. 
Cores are differently made according to their diameters. 
A small core is stiffened only with a couple of irons. A 
large one has a grid with prods. In a small one, the 
central vent is simply cut with a trowel in the joint after 
each half has been dried and turned over, while in a large 
one the central vent is formed by daubing the loam over a 
central body of green sand, first made roughly semi- 
circular with the hands. 

Fig. 180 shows the various stages in making a common 







Siiii^^^^^: 



Fig. 180. — Loam Pattern. 




socket bend in loam. Assume, for 
the sake of definite dimensions, that 
it is a 12 in. bend with ^ in. metal. 
Then the first thing is to lay down a guide iron, //, which 
may be ^ in. away from the outside, and of course 1 in. 
away from the core. Then the core strickle will have a 
1 in. check, B, Fig. 179, and the pattern strickle a I in. 
check. Weights will steady the guide iron. First a body 
of green sand, C, is made roughly semicircular with the 
hands. Then wet loam is daubed upon this and brought 
up to within about I in. of the strickle as shown. Figs. 
179, 180, D; a cast iron grid, E, being bedded in the loam 
at the same time. While the loam is yet plastic, a number 



260 PRACTICAL IRON FOUNDING 

of f in. or ^ in. holes are pierced through it, reaching to 
the interior. These are the main vents. When this coat 
of loam has partly set, the finishing fine coat is laid on 
and swept round with the strickle, as shown at F. It is 
evident that two such halves put together joint to joint 
and cemented, will form a properly stiffened and vented 
core. 

The enlargement in diameter at the socketed end is 
usually made by striking up a ring of loam and thread- 
ing it upon the core, its vents being brought into the 
main core vents. 

The next stage, if one casting only is required, is the 
striking of the pattern thickness upon the core. Nothing 
is moved, but the core is coated with black wash, and 
the loam struck thereon with the pattern strickle, as at 
II. This also is dried. 

The socket is variously made. Sometimes the thick- 
ness, forming the socket core, is not put on until after 
the pipe has been moulded. The socket body is struck 
and threaded directly on the plain core as at G, or a 
standard wooden or iron socket pattern is slipped over. 
Sometimes the socket is struck up on its own core, 
either by means of a guide ring. Fig. 180, /, which 
forms a portion of the pattern, and strickle, J, working 
thereon transversely, or the two separate diameters, 
I, K, are struck with two separate strickles working from 
the guide iron, and the curves by which they merge into 
one another are rubbed by hand with rasps and glass- 
paper. 

"When a pattern thickness is struck upon a core as in 
this case, it is usually necessary to secure the thick- 
ness firmly, during moulding and handling about, with 
flat-headed plasterers' or chaplet nails; without this 



LOAM WOBK 261 

precaution the thickness is apt to peel off at the black 
wash joint. 

When a pattern is struck, the diameters of which vary 
at every position, no single templet will shape it. Then 
strickles are made to the extreme diameters, and if the 
pattern is of awkward shape, strickles also for certain 
intermediate positions, and the loam is rubbed between 
these positions with files or rasps, the eye being the arbiter, 
with or without the assistance of sectional templets. In 
a reducing bend three such positions might be taken, 
one at each end, and one at the centre, and two guide 
irons would properly be used. The three strickles rest- 
ing against the guide irons would give the semicircular 
outline at each position, and the longitudinal outline of 
the guide irons would give the curves by which the 
joint edges of the cores would be imparted, the strickles 
for these being of a sectional form, giving the edges only. 

When the core has been rubbed down to its proper 
curves, the thickness is variously put on. Thus, strickles 
may be used at the ends and middle just as in the core. 
But this leaves the eye to judge of thickness, which in 
thin castings is too risky. Hence thickness pieces are 
fitted to the core, being either wood strips, curved or 
straight, gauged to thickness, or flat-headed nails are 
driven in by templet. These afford a guide by which 
the loam is daubed on and strickled off. All these are 
easily removed after the pattern is moulded and the core 
is required. 

The flanges on loam patterns are usually made in wood, 
and they rest against the shoulders of the loam which 
forms the pattern thickness. These shoulders are there- 
fore filed quite square after the thickness has been dried 
in the stove. 



262 PRACTICAL IRON FOUNDING 

In some loam patterns there is a great deal of this 
fitting of wooden parts, portions which cannot be made 
in loam being conveniently made in wood. A little knack 
and some rough geometry is often essential therefore in 
this class of work. Centre lines, and lines at right angles, 
which can only be struck with trammels or compasses, 
are often wanted, and their accurate laying down is 
rendered all the more difficult, because many loam pat- 
terns are unjointed. 



CHAPTER XIII 

THE ELEMENTS OF MACHINE MOULDING 

The elements of machine moulding exist in the use of 
turn-over boards, and in plate moulding, devices which 
are employed to a greater or less extent in nearly all 
shops. 

Turn occr hoards, joint hoai'ds, bottom boards, as they 
are variously named, are employed to facilitate the making 
of the joint faces of moulds. In ordinary work these faces 
are made by strickling and sleeking down, as noted on 
pp. 140-2 in connection with Figs. 64-70. But when similar 
work is often repeated the joint faces are rammed directly 
upon boards, the contour of the faces of which corresponds 
with that of the joint faces of the sand — flat, if required 
flat, irregular, sloping, curved, etc., if so required. In the 
simplest mould, the flask which is to become the bottom 
or drag is laid upon the bottom board over the pattern, 
rammed, lifted off with the pattern or portion of the 
pattern belonging thereto enclosed in situ, turned over, 
and the cope rammed upon it. This method is very 
advantageous in two cases: first, when the pattern is so 
flimsy that it would probably become rammed out of 
truth, or could only be kept with difficulty from winding 
during ramming; and second, when the parting joints 
are so uneven, unsymmetrical, curved, sloping, and irre- 
gular, that to cut and sleek them with the ti'owel at each 
time of moulding would entail much loss of time. 

263 



264 FILiCTICAL lEOy FOrXPIXG 

Plate mouldinii is an advance upon this practice. Using 
turn-over boards, the cope is rammed on the drag, joint 
to joint, in the positions which both are to occupy iinally 
at the time of casting. But in phxte moulding the joint 
faces are not brought together at all until the time of 
final closing. The pattern is divided into two portions, 
one portion being upon one side of a plate of wood or 
metal, the supplementary portion being upon the opposite 
side. Or in many cases distinct plates are employed, each 
carrying that portion of the pattern which is the supple- 
ment of the portion on the other plate. Cope and drag 
being rammed, each on its respective side of the plate, 
or on its separate plate, form when brought together a 
complete mould, corresponding at the joints. Thus, taking 
an example, the trolly wheel shown in Figs. G-l-GT, p. 141, 
would, if moulded on a plate, be made as in Fig. 181. It is 
clear that the portion of the wheel on the face B of the 
plate is supplementary to that on face C. The faces B and 
C form the joint faces of the drag and cope. Patterns like 
these are arranged singly or in series on plates, accord- 
ing to size and quantity required. A pattern of large size 
will occup}^ a plate to itself; several small patterns, alike 
or dissimilar in character, may be arranged on one plate, 
and poured from a central ingate and spray of runners. 

The difference between the solid pattern used on a joint 
board and the divided pattern on a plate is due to the 
difierence in the methods of moulding. In the first case, 
one-half the mould is rammed on the other half — the 
latter being the one which is rammed on the board. In 
the second case the mould parts are rammed independ- 
entlv of each other, and thev do not come too;ether at all 
until finished. In both cases there is much economy 
over the ramming of patterns by the ordinary method of 



THE ELEMENTS OF MACHINE MOULDING 265 

turning over, in which the joint has to be prepared by 
the trowel of the moulder. Both in joint board and in 
plate moulding the joint is made at once by the face of the 
board or plate. But the latter also saves time in the lift- 
ing out of numerous patterns, besides which it is a more 
permanent arrangement, and one moreover that lends 
itself to still further economies, as arrangements of run- 
ners and the use of separate plates for top and bottom 





SECTION A-A 

Fig. 181. — Plate Moulding — Trolly Wheel. 



boxes. Also the system is more adaptable to the pre- 
paration of patterns and plates in which the joint faces 
instead of being flat are sloped, curving, or otherwise ir- 
regular in contour. 

Patterns are dowelled on plates (Fig. 182) just as they are 
when moulded by bedding in or by turning over. Usually 
the dowels are made long enough to pass right through the 
plates into the holes of the other half pattern. The pat- 
tern halves are fitted up with their dowels and are tooled 
and finished before being attached to the plate ^, which is 



^H\{) 



rincricAL //,7>/v h'oi'NniNii 



usii.'illy (lone willi sciiuvs, or livcls, l*'i}^. IS'J, sonictiindK 
with H()l(i(U-. Ill :i, |)|;iio .1 liiUul ilniM wiili |);i,l,l,(U-ii |):m(,s 
on opposito Hides (,li(> hoxc^s iiic colicu-cd lo llic |)I:il(^ niul 



/c 



V. 



I 



n 




d 



o 



^ 



f 



•vl. 



n 









•'••H-:<'.'.;".,l:':V;v^ 



iw 



V\(\. iSti. PaI TKICN 1*1, ATM ON l»()\. 

soraiimicd, l^'i^. |S'J. Tlio coIIcm-s wxv [\\k\\\ kiiockiMl oiifc 
and tlii^ l)(>\t>s itunoviul mikI closed lor pourin*;'. Hut 
separate platos \\\\\ ofiiMi used so Ihai two sots of nion rail 
iKnvorkiiij;- on oiu^ class of castin<^s. Tlu^ positions of tlio 
patt(u-n parts aro tluui set o\\ tlu^ Boparato platos by 



TJfH h:LI<:MENTH 0/' MACHINE MOULlJfNd 267 

centre lines, and the box pinn located properly ho that 
when the half moulds are prepared they will come to- 
gether without any overlapping joints. When patterns are 



..Jc 



D\. 



< 



QQQ 



oC= 




0)©6666 



3 



VEI^T 

FkJ. iH'i. — AUKANWJEMENT OF SmAJ.J. 1'aTTERNH 
AND KUNNEHH. 

moulded with irregular joint faces the original pattern is 
rammed within a suitahio box and turned over and the 










;3 



Fid. 184.— AuJtANOEMENT OF PATTERNS AND RUNNEKH. 

other side rammed. Then a frame, prepared to the thick- 
ness of the intended plate, is laid on the joint face in the 
box and rammed round its edges to give the size and 
shape of the plate, and the mould poured, so producing 



2(;h 



l'ir{<"ri('Ah Ih'ON FDl^NDlNii 



II pljiic ill Olid wiili ils pa.llcrii. 'riicid in no oHHciiiinJ 
(lilloriMK-c ill |)l:il<(f-nioiil<liM<; n.iid in nioiildin*', doiu^ on a 
ni!i.('liiiM\ in liicl. Ilic pliiicH will ri('<|miiil ly inUucIiMiij^d, 
tind in llid caHc of snnill |t;i,l.l,(^rn:i m(W(M'm,I iiro nioiinl.cd on 
a, \)\\vU\ n,H in I*\'^'h. iHii i,o \H{\, nnd I1i<> riinnoiH mJho arc 
Hiiiialdy diH|)OH(ul (lidrcon. l*'i;^H. iHli l,o IS I arc hIiowii aw 
ihouf^li niounicd for |»la(,(>-inonl(lin^; in oidiimiy hoxoH, 
liavin«;- liand IioIom, a^nd JioU^s for l.lic l)o\ |)iiis. I''i;^. 185, 
luivin;^!; no li(doH,nn'^liL hv a.tiacliod to w nioiildin;^ nuicliino 
in vaj'ioiiH wnyM, willi (dips or oIIhuw is(\ Mho l''i<';. IHI 



r 1 



(( )) (T )) <c7) <o) Q ■(') 






ir 



U "JL 



l''l«J. |S^. A IvMv'ANdl'lIM lON'P ()K PA'iriOh'NS AN I) Ivll N N i; KM. 

niij^lil, K'prcsi'iil, a niii'^lo plalo wiUi pailcrns on ono nidd 
only, l,\vo phiU'H Ixmii;; used on dilTor(>nl, boxes, (H" llio iwo 
sidoH of llid saiiHi |)lal(^ niijdil, he alike. I<'i«;. IHC) hIiowh 
anvil jaws j)la,i(ui lor iiso on a, nnudiinc 

l*'i[^. IH7, IMaic \', icprdscnts a, pa,i(.cM-n-|>la,l,(M)l" a, loco- 
inolivc wheel in Uie backj^round, while ihe halves of tlui 
mould nunle IVoin it a,re seen on ihe }'i()iind in IVoiii. 
I*'i<^s. \HH and IS!I, Tlaie V, also show paUc^ni pla.icH; 
the liisl, is l.hal of a. spiixdud; wheel, (,iie halves of whicll 
are on oiu^ side of a. phiie. W ilJi two laniininj^H iwo 
wheels are moulded. 'The lowcu- lij^^ure is lIuiL ol' a lioiloi* 
(h)oi-, ma.de on iwo st^paraie plaitis. 



77//'; i<:ij<:MJ':NrH oi'' mahiiini': MoiiLinNa 'im 



Tho utility of a inoiddhuf marhhw ^'.oriHiHiH larj^(;Iy in 
thiH, thai/ in \>\;\,cAi of tho cJurnHy juid oftfjn iruiccurato 
Hoparution of tlio f)attorri plat<;H frofu th(i llankH hy fiand, 
i\i(iV(i in HiihHiiliitod Llui HLcady, (•.({\iii\, and [><;rf(;ct H^jpara- 
tiori by rnc.fdianiHrn. Home, of tfirj inoro UHoful rnacfn'ncH 
iiicludr; jijiicfi nior<; Ui;uj UiiH, an tho ramming or prcHHin^ 
of tho Hand ;uoijn'] ilio pattornH, and tho nna of Htrippin^ 
I)latoH, that in, [)latoH through whicJi ifn; p;iit(;rnH aro 
drawn, thr; j)hit(;H HiiHtain- 
in^ tfu! HM>nd and prcjvonl- 
in^ hrokfifi (;d{^(;H; fjut hucIj 
ohihorjition \h rjot OHHorj- 
tial to rri;i/'Jjin<; rriouldinj^, 
tfiouj^fi oftf'fi <'-onvonir;nt 
and advantaj^rjoiJH. 

Tho r;ipid ^'rowtfi of rn;i,- 
chine rnoiildinj^' iH onr; of 
tho rnoHt r(!rnarkahle f^-a- 
turriH of p)o,H<5nt fourjdry 
practice. Tfic; rnachinriH 
mado now nunihor wevoral 
scoreH of distinct dcHi^nH, 
though tin.* hroad typOH 

may ho roducod to Iobh than a dozen. To undorHtand 
thri oHKontial difforoncoH hotwoon tlioHo typoH it in an vv^Jl 
to (;onHid(;r tho prinoij)al Htaj^OH in mahinj-^ niouldH, which 
includo rarnminj^, tmninj^ ovor, rappin^^, and withdrawal 
and cloninj:^, tljo diraonHionn of mouldH, and tho canr; of 
ropotitivo work. l\:i(:\\ of thoHO awpoctH of moulding han 
occaHionod tho ovoJution of hroad and diHtinct typoH of 
niachinoH, wfiilo many machinoH aro huilt to comhino 
moro than ono of those cardinal foaturoH. 

lio/niminff. — 'V\\\'n in tfjo Buhjool whicfj naturally arisoH 




\'t<i. \H('>. ASVIL .Ia WH 
AUUANOKO ON I'l.A'lt:. 



270 rh'M'TKWh Ih'ON h'i>liNniN(i 

(irsl, ill Miiy (jiKiHiion of miicliiiKMiioiildiii'^j. Hcu'jujhc^ it iH 
Llid most (lilVicJili ('(^niiiiM^ io (Uiibody in ii iiiacliiiK', iH ilio 
rojiHon wli.y, noiwiiiislaiuliii}^ liuiidrcdH of paidiiicul do- 
vic(^H, only a, iiiinoriiy of nnudiincs i()-(la,y includi^ ])r()- 
vi.sion i\)v ('()iii|»l(i(,(i niccliajiical iiumiiinj';, Ilioiif'Ji l\\i\ 
nimilMW iM iiicica.sini^. 'Tlic iiiajorily iwo still hiiill, for 
hand ra.iiiiiiin;!j, tli()ii;';li iluisii nsiia.lly includes a, prcsHci" 
head, MO IliaJi Ux^ ii(<iliLi(^s of i\\c inoiildin;; ina.cliiiu's li(^ 
niji.inly in oilici- fcalui'ivM. Tlio (ixcc^plions io IJiih f^cncra,! 
rul(^ liti chitilly in soiiio H|)(H'ia,l chisHOH of work \vlii(di a,r(^ 
la,r^(dy r(^|)(^l,il,ivo, in coiisckjiioiuu^ of \vlii(di considoraJdo 
oxpcnsc can be incnricd for MocKh liavin;;" iri('}!;nla,r con- 
liOiiis, nioi(^ or loss a,|)|)ro\iina.iin<!, io IJic forni of I.Ik^ 
pallcin, and by means of wliicli (be forciM)!' ra.niminjjj can 
be j^radnalcnl. Sonioibiii'jj of ibis kind is osscniia,!, tb(5 
ca.s(^s of sballow i)a,iiorns (^xcopicd, oi- iliosc^ wiib biii'ly 
bu'cl biccs ov(M' wbicli ilu^ sa,nd can l)o pressed antl con- 
Holidaied cujinilly by a. llai pressiii}'; plaie. It hcumiih 
hardly necessary io (explain the rea,son of l,liis. The 
moulder knows W(dl how the force of raniiuin}^ is va,ried 
coniinually, a,nd alinosi unconsciously owv different 
sections of (he same nu)uld, as well as in luoiilds nia.de of 
dilVeriMii niixtui"(^s of sa,n(l, a.nd (Jial such ra,nniiin<>; is 
done sideways in under(Mii portions under lla,ii}j;(!S, lu^ijs, 
bossies a,nd so on, work which no nni(diine ca,n iinitatt^ 
])(^rf(H*tly. Still it may b(> staited tluit a,l most any class of 
work, e\(Mi tbou'di in(>{!;ula.r or intiica.te, can \h) ra.nuned 
by |)ower if the number of ca,stin;;s KMpiired off is sulli- 
cicMitly numerous to warrant tlu^ cost of raniminj!," a.|)pli- 
anccss. Tlu^ (pu^stion then is one of r(da.tiv(^ cost, as in 
smiths' sta.m|)ing dies, and in machine shop ii<j;s. 

The rcMisons for adoptin;^" imichiiH^ rajiimin*;- a,re most 
co«j;ent wluui the joints of moulds aio of irrc^gular out- 



THPJ hJLimKNTH O/'' MACHINE MOVLBINO 271 

lineH, that j'h, when the faces of the jointH have to nlope 
njnvardH and downwardH, with phine or curved outHneH 
to follow pattern partn wliich Htand ahove or Ijelow the 
^en(;ral plane of tlie moulding-box joints. These irregu- 
lar joints, when made with tlie trowel and the moulder's 
hands, often occupy a considera}>le time, and they have 
to he repeated for every mould unless a ramming hoard 
or hlock is prepared and used for moulding on. When a 
pattern plate, made in a similar way, is put on a mould- 
ing machine, the economy of power ramming is very 
gi-eat. And further, on the same joint plate, runners, 
or sprays of runners, are usually arranged once for all, so 
(;ffecting a further economy in time. 

Turnirui-ovar. — The turning-over of the parts of mould- 
ing boxes, when done by a machine, avoids the risk of 
the sudden shock and fracture of sand which sometimes 
follows from a clumsy turn-over done by hand. Some- 
times it is the pattern plate alone that is turned over, 
soujetimes the moulding box on the plate. But in any 
(•,aH(; it is always done steadily, and the plate, or the box, 
is locked in a truly liorizontal position, and also at a 
height convenient for working at, instead of lying down 
on the ground. This last is one of the less appreciated 
features of macliine moulding, but it nevertheless has 
considerable advantages. 

'J'he turn-over table is fitted to the greater number of 
machines designed for general use, because it affords the 
handiest method of ramming tops and bottoms. But as 
machines increase in dimensions, its weight becomes 
objectionable, and the largest machines therefore, as well 
as many of medium sizes, employ a non-turnover type of 
table. Then tops and bottoms can be rammed on separate 
machines, or on one machine at different times, or at 



272 PRACTICAL IRON FOUNDING 

the same time if the length of the tahle is sufficient to 
receive two boxes side by side, which is often arranged. 

A large machine, with a non-turnover table, is often 
preferred to two or more smaller ones, because several 
patterns can be moulded at one time on one or on 
separate plates. This is an extension of the method 
adopted in hand work, of arranging several small 
patterns in one moulding box, or on one bottom board or 
plate. 

Rapping and Withdrawal, — The delivery of patterns 
from moulds when done by hand is commonly a cause 
of enlargement, and variations in the sizes of moulds, 
and often of fracture of the sand, which when mended 
up tends to produce variations in the dimensions of 
moulds. The larger a mould is, the more risk is there 
of such accidents happening, because of the difficulty of 
getting a truly level lift when two or three men are lift- 
ing at once, or when the crane has to withdraw a pattern. 
The principal value of very many moulding machines, 
therefore, lies in the simple fact that patterns and 
moulds are separated by the coercion of rigid slides in- 
stead of by the unsteady action of the human hand, or of 
the crane. So valuable is this feature that many mould- 
ing machines embody no other provision besides this. 
Subject to the condition that patterns are made well, 
there is no fracture of sand, and a hundred moulds 
made from the same pattern will show no variations in 
size. 

But there are aids to the withdrawal of some kinds of 
patterns which are essential. A deep pattern having 
little or no taper or draught cannot be withdrawn with - 
out tearing up the edges of the sand unless some rap- 
ping or vibration is imparted to it, or unless a stripping 



X 

Ah 




02 
H 

fin 

H 

H 

(1h 

o 
-^ 



o 

M 



THE ELEMENTS OF MACHINE MOULBING 273 

plate is used to hold down the sand around its edges. 
Shallow patterns and those which are well tapered can 
be withdrawn readily if the machine plate on which the 
pattern is mounted is rapped with a wooden mallet 
during the act of withdrawal, and this is usually done. 
But that is a different thing from the lateral rapping 
with an iron bar inserted in the pattern, and which is 
imparted previous to the lifting by hand of the pattern 
from an ordinary mould. Kapping on the plate merely 
loosens the sand next the pattern and prevents its ad- 
herence. But slight enlargement of the mould, imitat- 
ing the action of the rapping bar is provided for in the 
jarring or vibrating class of machines in which slight 
lateral rapid movements are imparted. 

The majority of machines have no provision for vibrat- 
ing the pattern, but when deep lifts have to be made of 
patterns provided with little or no taper, a stripping 
plate is made to encircle the pattern closely. It is laid 
on the face of the mould and the pattern is withdrawn 
through the plate. This is an extension of the method 
often adopted in making common moulds by hand work, 
when strips of wood are laid down along the edges of 
the mould beside the pattern, and retained by weights 
during the withdrawal of the pattern. The sand around 
the edges is thus prevented from being torn up by the 
lifting of the pattern. Frequently metal stripping plates 
are used for hand moulds, as in machine moulding, — in 
some gear wheels for example, both of spur, and special 
types. These are rather expensive, being filed out of 
sheet metal to embrace and fit the pattern outlines, 
hence they bear a high proportion to the cost of the 
castings unless a large number are required. But many 
are made now cheaply by casting white metal within an 

T 



274 PRACTICAL IRON FOUNDING 

iron frame surroundmg the pattern. And so when the 
maccuracies which result from hand rapping and with- 
drawal are eliminated by machine moulding, castings 
are more uniform in size and shape. Hence the allow- 
ances for tooling can be lessened, with reduction of costs 
in the machine shop. 

The idea of drawing the pattern through a plate has 
been familiar for the past forty years or more, even in 
hand work. The late Mr. James Howard, of the firm of 
James and Frederick Howard, of Bedford, took out a 
British patent for a moulding machine worked on this 
principle as far back as 1856, and that firm has used 
machines of this type ever since for the bulk of their 
repetition work. 

Closing. — Moulds are usually closed by hand. But a 
few machines are made to fulfil this function after the 
removal of the box parts from the moulding machine. 
There are, however, apart from this, many adjuncts to 
machines for taking the finished moulds away for 
closing them, as trolly tracks, turn-tables, etc. 

Dimensions. — The dimensions of moulds impose some 
limitations on the sizes of moulding machines, though 
a large increase in size has been noticeable in recent 
years, chiefly in some American and German machines. 
All the early machines were designed only for dealing with 
articles of small dimensions, not exceeding from about 
2 ft. to 3 ft. across, and the greater number moulded were 
even smaller than that. The reason is obvious, since 
the first machines were operated by hand alone. After 
power was applied, dimensions increased, and the largest 
machines now, which will take lengths of 10 ft. to 15 ft., 
are operated by hydraulic pressure with the greatest ease. 
A large machine has the advantage over a small one 



THE ELEMENTS OF MACHINE 3WULDING 275 

that it is adaptable for dealing with single moulds of 
the largest size within its capacity, as well as with two 
or more separate moulds of smaller dimensions, thus 
combining in one the advantages of two machines. 

Repetition. — The production of repetitive work on a 
large scale has been the cause of the development of the 
portable types of machines, of multiple moulding, and 
of numerous adjuncts to fixed machines of ordinary and 
of special types, such as tracks, conveying systems, 
cranes, etc. This aspect alone opens up a very wide 
field of interesting detail which illustrates the numerous 
and varied ways in which similar results are secured. 
For though the small light machines may be moved 
along the floor, leaving their work behind them, the 
large heavy ones must be fixtures, and the work must 
be brought to and conveyed from them. Conveying 
systems also deal with the sand and the moulding boxes. 
In some shops these systems have become very highly 
developed. 

Adaptability. — The practice of machine moulding is 
adaptable to all classes of work that lie within the 
capacities of the machines. Like die-forging, it is suit- 
able alike for a limited number of articles only, or for 
hundreds or thousands of similar parts. And the cost of 
the pattern work is mainly controlled by the numbers 
of castings required; ordinary cheap patterns of wood 
for a few moulds; high-class, well made patterns of metal 
when hundreds or thousands of moulds have to be taken 
therefrom. So that moulding machine practice ranges 
from that in which ordinary patterns are mounted on 
plates, as in the plate-moulding which is done by hand, 
and put on the machine, to those in which metal patterns 
on plates are got up in the best possible manner for use 



276 PRACTICAL IRON FOUNDING 

on the machine alone. And between these extremes 
every grade and method of pattern work is represented 
in machine moulding. Formerly, too, only simple pat- 
terns were attempted, but now many intricate forms are 
used. The simplification of the moulder's task also 
follows, with the result that men who have not had 
the moulder's training, or mastered any section of the 
moulder's craft, are able in a few weeks to operate 
machines. 

Patterns.— A^ in ordinary hand moulding, patterns 
are either unjointed or jointed. In the first case a plain 
top only is wanted, and then the pattern is mounted on 
one side of a plate. In the second case the pattern parts 
or halves, as the case may be, are mounted on opposite 
sides of one plate, or each on one side of two distinct 
plates, which may be moulded on the same machine by 
one man, or on different machines by different men. 
The matching of the moulds depends on the degree of 
care and accuracy with which the pattern maker has 
done his work. Each of these methods is also adopted in 
much hand moulding when it is of a repetitive character. 
Another fact is that in moulding by machine it does not 
matter essentially whether the pattern is lifted from the 
mould, or whether the mould is withdrawn from the 
pattern, and whether upwards or downwards. Neither, 
as already stated, is turning over on the machine an essen- 
tial. The details vary with types of machines. 

A point to be emphasized is the futility of pinning 
one's faith and practice to one class of machine. No 
matter how excellently designed and economical a machine 
is, there is always another that will go a point better on 
certain classes of work, and operated under different 
conditions. That is the reason why a firm should feel 



THE ELEMENTS OE MACHINE MOULDING 277 

its way in laying down plant of this character, and not 
order a lot of machines of one type, if the range of work 
done is of a varied kind. The case is paralleled by that 
of machine tools. No sane manager would fill a shop 
with machines of one build and type, unless, of course, 
the character of the work done was uniform, as in the 
case, say, of ranges of screw machines, or gear cutters, 
always operating on the same kinds and nearly the same 
sizes of work. 

The question of type of machine then opened up is a 
very wide one. So is that of dimensions. So, too, is 
that of method of operation. Thus, if men work regu- 
larly on separate parts of the same moulds, on separate 
machines, there is no need, as a rule, to have turn-over 
table machines. Nor when tops are uniformly plain 
are turn-over machines necessary. Nor when the two 
parts of moulds are made side by side on one plate, or 
when a number of tops and then a number of bottoms 
are made on the same machine, is it necessary to have 
a turn-over table. 

With regard, again, to dimensions, the size of a single 
pattern alone is not only the governing question, since 
it is often more economical to put several patterns on 
one large machine than to have single patterns on smaller 
machines. This holds good not only in relation to very 
small patterns that are commonly grouped thus, but 
to those of comparatively large dimensions, which can 
be moulded on oblong machines of several feet in length. 
Another advantage in using such machines is that top 
and bottom box parts may be, and often are, rammed 
on one side of one plate at once, not of the turn-over 
type. 

The method of operation is an important governing 



278 mACTTCAL TT?ON FOUNDTNa 

condition when we get into machines of very large 
dimensions, for it is obvious that however well counter- 
balanced a table may be, and though human power may 
bo multiplied and used to the best advantage, with 
levers and with worm gear, there is a limit to its em- 
ployment beyond which hand operations cannot be 
conveniently and economically carried, and this is the 
opportunity for the power machine, and this raises the 
broad question of power operation. 

Generally this should be settled by the character of 
the plant already existing in a shop, or of that which 
it may be contemplating to lay down. All progressive 
foundries are now equipped with power of some kind, as 
steam or water power for cranes, air or electricity for 
hoists, and other purposes. Of hydraulic moulding 
machines there is an immensely greater choice than there 
is as yet of steam or of pneumatic machines. But in 
view of the recent rapid growth of air-operated machinery 
which has been shared by the foundry in common with 
other departments, we may anticipate that pneumatic 
moulding machines will be in much greater demand in 
the future than they are yet. If the question is one of 
laying down power plant in a foundry as yet unsupplied 
with power, it may be pointed out that a pneumatic 
plant is less expensive and less bulky than a hydraulic 
one. Air-compressing plants are very suitable for small 
foundries, and they serve also for hose-piping for blowing 
out moulds, in place of bellows: and a few air hoists 
also are more handy than iixed hydraulic cranes. None 
of these questions can be settled offhand, but each separ- 
ate shop must work out its own problems, independently 
of the governing conditions of others. 



CHAPTER XIV 

EXAMPLES OF MOULDING MACHINES 

Fig. 190, Plate VI, illustrates one of the simplest 
machines that can be made, being a mould press simply. 
Ordinary boxes and snap flasks are moulded on it, the 
latter being shown in place. Preliminary ramming may 
or may not be done by hand, according to the outline of 
the pattern. The final pressure is imparted to the top 
and bottom of the moulds, to which presser-boards are 
fitted, by the downward pressure of the hinged head, 
actuated through toggle levers by hand. The levers on 
opposite sides of the machine are connected by a hori- 
zontal shaft. The height of the presser-head is adjusted 
to suit boxes of different depths by means of the nuts on 
the screwed rods. There is no mechanical delivery, 
patterns being rapped and withdrawn by hand in the 
ordinary way. But the saving in time is very consider- 
able on repetitive work. 

A hand machine of more advanced type, which has 
been in successful use during many years, is that manu- 
factured by Messrs. Darling and Sellers, Limited, of 
Keighley. It is made in a large range of dimensions, both 
for general work, for specially deep work, and for strip- 
ping plates. The machine is designed for hand ramming, 
and no special pattern plates are necessary, since any 
patterns of suitable size, either in wood or metal, can be 
mounted on the table. The illustration, Fig. 191, Plate 

279 



280 PRACTICAL IRON FOUNDING 

VI, shows one of these machmes, which is specially de- 
signed to take deep and heavy boxes, with which object 
it is made rather differently from those which are built for 
small and medium work of a general character, as in Fig. 
192, Plate VII. It will be noted that though the general 
design is similar in both instances, the differences are 
that gearing is used in Fig. 191 for operating the turn- 
over table, and that the elevation is done by racks and 
gears instead of by simple movements of a lever, as in 
Fig, 192. But with these exceptions the same general 
description will apply to each. 

The two standards in these illustrations carry the 
mechanism between them; they are built at various 
distances apart, ranging from 30 in. upwards to about 
16 ft., to suit boxes of different lengths, and are main- 
tained apart by stretcher bolts and a bottom casting, 
while the larger machines are also bolted to a base- 
plate. The pattern is fixed to the upper face of the top 
table, which is of the turn-over type, and the box is 
placed over this and rammed by hand. It is retained in 
place by means of screws and sockets which are adjust- 
able for different depths of boxes, or in the case of light 
work, by spring clips. The table is fitted with trunnions 
of large diameter, in capped bearings in the standards. 
Set screws, with large nuts, afford the means by which 
the table is adjusted for level without further check, and 
it is prevented from moving by the catch handles above. 
In the machines for general service the trunnions are 
placed in the centre of the table, as in Fig. 192. But 
in the example in Fig. 191 they are placed eccentrically 
in order to come more in line with the weight of the 
pattern and moulding box. But they are arranged in or 
out of centre, in either machine, to suit requirements. 



EXAMPLES OF MOULDING MACHINES 281 

When the pattern has been rammed, the catches above 
are removed, the table is turned through half a revolu- 
tion and relocked, leaving the moulding box with its 
contained mould and pattern suspended from the under- 
side of the table. At this stage another portion of the 
mechanism, the lifting table, the bottom one, in both 
figures, is brought into operation. This is a ribbed plate, 
underneath which two turned stems or pillars, seen in 
Fig. 191, are attached with bolts through flanged ends 
on the j)illars. These are the means by which the 
lifting table is elevated and depressed through the 
action of slotted links hidden within the base, actuated 
by two levers on a horizontal shaft, which is turned 
by the long lever seen to the left in Fig. 192. The total 
mass of these parts is counterbalanced by the weight 
seen at the right. The effect of moving the lever is to 
bring the table up towards the back of the box that has 
just been rammed. In the deeper class of machines 
shewn in Fig. 191, the table is lifted by cylindrical racks 
seen beneath. These slide in bored sockets, and are 
actuated by the hand wheel and gears to the left of that 
illustration. The raising and lowering of the table are 
performed with ease, because the weight of the latter, 
together with that of its load, is counterbalanced by 
adjustable weights, which descend into the founda- 
tions. 

The table is lifted up until it presses the carriage 
against the back of the rammed box. The clamps are 
then released and the table lovv^ered, the mould descend- 
ing with it away from the pattern. During the period of 
this delivery the upper surface of the turn-over table is 
rapped with a mallet to assist the separation of the 
pattern from the sand. 



282 PRACTICAL IRON FOUNDING 

The mould is now left lying on the carriage, imme- 
diately above the lower table, on which it is drawn away 
by means of rollers beneath the latter, not visible, to the 
receiving rails in front, which, being clear of the machine, 
permits the mould to be lifted off and taken away. 
The carriage is of wood, and its movement is controlled 
by flanges on the ends of the table. The receiving rails 
are similarly flanged, and form the top edges of cast- 
iron brackets, which are bolted to the front of the 
machine. The empty carriage is now pushed back on 
the lifting table, and the* turn -over table revolved to 
bring the pattern on its upper face ready for the 
next box. 

Front and back plates enclose the lower portion of the 
machine. These are fitted by planed joints to the 
standards, and serve the double purpose of bracing the 
machine and preventing sand from falling inside. 
Inner sloping top edges of these plates shoot off any sand 
that falls from above. A handy table is supported on 
brackets at one side. Fig. 192, to carry the moulders' 
tools, swab pot, blacking bag, etc. 

A machine of this kind is of great value in any foundry, 
even where few specialities are handled. Any ordinary 
pattern within its range can be taken and put on the 
table and moulded with a perfectly vertical lift. It will 
pay to use the machine for two or three moulds only. 
When a plain top only is required, the latter can be 
rammed on the plain table. When patterns are jointed, 
their halves or parts must be fitted on opposite sides of 
the table, or be fixed on separate machines, which in- 
volves some fitting that would not be justified for two 
or three castings, though in this respect the machine is 
quite adaptable in firms that have not much specializa- 



EXAMPLES OF MOULDING MAC TUNES 283 

tion. But outside of these there are many cases in which 
the patterns are cast with the turn-over or swivel ta,ble, 
as in labour-saving repetition work. Patterns are 
specially mounted in three ways — on a falsn-part box, or 
on thin cast-iron plates exactly as used in many shops 
for plate moulding without the assistance of a machine, 
or mounted in plaster-of-paris. 

In all these cases the piece carrying the pattern or 
patterns is capable of being attached simply and rapidly 
to the turn-over table by a couple of bolts, and the usual 
practice is to mount the bottom-part pattern on the 
table, make the required number of half-moulds, and then 
replace it by the top-part pattern; the change of patterns 
being only the work of a few minutes. 

Messrs. Woolnough and Dehne's moulding machine, 
manufactured by Messrs. Samuelson and Co., Ltd., of 
Banbury, is illustrated in Fig. 193, Plate VII, and Figs. 
194 and 195, p. 285. Fig. 193 is a perspective view of 
the machine. Fig. 194 a sectional elevation of one of the 
standards. Fig. 195 a horizontal section through the 
standard on the line A-B. A base plate. Fig. 193 carries 
a couple of pillars, one of which, that to the right, is 
permanently fixed, the other, to the left, is capable of 
horizontal movement, rendering the machine adjustable 
to the width of any pattern plates within its range. The 
pillars A, are hollow, enclosing spindles B, to which 
vertical movement can be imparted by means of the 
weighted lever handle seen in Fig. 193. The lever actu- 
ates the horizontal shaft H, Figs. 194 and 195, upon 
which are keyed two worm wheels F, enclosed in the 
semicircular casings G. The shaft and casings are seen 
at the front in Fig. 193. The worm wheels engage with 
screws cut on the vertical spindles B, and so raise and 



281- PRACTICAL JUON FOUNDTNG 

lower the pattern plate, which has its bearings, c, in the 
upper ends of the spindles, and which can be turned over 
in its bearings. Two triangular plates furnished with slots 
and bolts for vertical adjustment slide in faces upon the 
pillars, Fig. 193, and their upper edges form the tracks 
for the wheels of the plate, upon which the moulding box 
is supported. The provision for vertical adjustment per- 
mits of the employment of flasks at various depths. 

The method of moulding is as follows: That face of 
the pattern plate from which the impression is to be 
immediately taken, whether for cope or drag, is turned 
uppermost, and the appropriate flask placed thereon and 
clamped or screwed. The sand is then rammed in by 
hand, and scraped level. The flask and plate are turned 
bodily over and lowered, until the back of the flask rests 
upon the table beneath. The pattern plate is then pinched 
in its bearings with the set screws seen at the tops of the 
pillars, and lifted clear of the flask by the lever handle. 
A very slight amount of rapping is imparted to the pat- 
tern plate in the act of withdrawal. When the mould has 
been blackened the pattern may be returned temporarily 
in order to press the blackening down, thus saving the 
trouble of sleeking. 

The sleeve, Z>, Fig. 194, is simply for the purpose of 
protecting the vertical spindles from access of dust, and 
a screw gland, K, similarly protects the worm and worm 
wheel. 

Fig. 196, Plate YIII, shows a machine of a similar type 
by the London Emery Works Company, carrying the 
pattern for tramway axle boxes, castings of which are 
seen in the foreground. The tubular standards each en- 
close a flat threaded spindle, the top of which is formed 
into bearings to receive the trunnions of the turn- over 




1' 




!y-i-M--if 



^ 



35« 












I ■ i , i f?J B - . -j'ii .l. 






Fig. 195. 



Fig. 194. 



WOOLNOUGH AND DeHNE's MOULDING MACHINE. 

Sectional Views. 



286 PRACTICAL IRON FOUNDING 

table on which the box parts are rammed. The racks are 
moved in unison by the long weighted hand lever seen at 
the left, which lever is adjustable by bolt holes into five 
different angular positions to suit different amounts of 
lift. The moving mass is counter weighted at each end ; 
the chains to which the counterweights are attached lead 
off from pulleys one on each end of the gear shaft below, 
leading to pulleys above. The box being rammed upper- 
most, by hand, is then turned over, and lowered by the 
lever on to a trolly below, the box being ran away after 
the pattern has been delivered. 

The general type of the Pridmore machines is that in 
which the table does not turn over, and in which a strip- 
ping plate is used in all except shallow work. A frame 
standing on the floor by legs, or a claw foot, carries the 
stripping plate, and is fitted with a yoke or plunger 
which carries the pattern, and by means of a crank or 
cranks operated by a lever, the yoke is drawn down or 
raised with the patterns. The depth of draw is capable 
of adjustment, and the pattern can be adjusted for height 
in relation to the stripping plate. No vibration or rapping 
is required. 

The broad plan followed in the construction of the small 
and medium-size machines may be clearly understood 
from the photograph Fig. 197, Plate IX, which shows, 
to the right, one of the smaller sizes of "square " machines 
with a pattern mounting, to which further reference will 
be made; and a rock-over machine to the left of the figure. 
Figs. 198 to 200 illustrate one of the 12 in. "round" 
machines, in side and front elevation and plan respect- 
ively. The essential construction of each is identical, 
unafi'ected by the square or round shape of the framings. 

The design is that of a main frame, A, formed of a 



EXAMPLES OF MOVLBING MACHINES 287 

single casting, and a pattern-carrying yoke, B, consist- 
ing of a second single casting, which is lowered and 

f 

JI 



c 






1 



u 



r^^ 




Fig. 198. — Pridmore Machine. Side Elevation. 



raised within the main frame by a crank, C, and pitman, 
D. The yoke, B, is guided at the top in adjustable ways, 
ciy a, and ai the bottom of the frame in a round, brass- 
bushed guideway, h. The distance betw^een the upper and 



288 



PRACTICAL IRON FOUNDING 



the lower guides being great in proportion to the width of 
the frame, ensures a true draw. The crank- shaft, E, upon 
which depends the weight of the yoke and the patterns, 




Fia. 199. — Pridmore Machine. End Elevation. 

through the crank and pitman, is journaJled in a long 
brass-bushed bearing, F, extending one-half of the width 
of the machine, and cast solid with the main frame. The 
yoke when raised is locked securely in position for ram- 



ss^ 



X 




EXAMPLES OF MOULDING MACHINES 289 

ming the mould by the crank passing slightly beyond 
the centre and bearing on the edge. The amount of draw 
can be adjusted to the height of the patterns by a simple 
bolt, G, and set-nut. Any wear upon the crankshaft or 
pin, or yoke pin, can be taken up by an eccentric brass 
bushing on the yoke pin, with a series of holes register- 
ing with differential holes in the pitman, M, so that all 
wear can be adjusted to one-five-hundredth of an inch. 




Fig. 200. — Peidmore Machine. Plan. 



Wear on the guideways, a, is taken up by adjustable 
plates, K, which are set along horizontally and pinched 
with the bolts, (/. The machine is supported on a claw 
foot, L. 

The various types in which these are made are as 
follows, classified broadly as *' light" and ''heavy" 
machines: 

The light machines, supported centrally on a claw- 
like foot, are of either round or square outline. The 

u 



•290 PRACTICAL I WON FOnNDJNG 

round onoH uro madi^ to tako eircuilar ])aifcornH, Huoh as 
•^i^ar wluH^ls, [mllt^vH, iiiid hiiiiilar claHHdH of work — in 
tlianioitu-H ra,iifj,in{^ I'roiu 10 to 'JO in., jmkI wiili m, depth (d" 
face H(»l e\i'tH\(lin.L^ lO in. Tlu" depl.li of drn,\v u^ 1^ in. 
Tlic vt»lv(i is coidrollcd lt\ two ^iiidowayH abovo a^id oms 
ill llic i(^iitrt\ willi a hiiij^Ic ciiiiiK. 'I'lio H(]uar(» <hi(\h mIho 
take 10 ill. ill depili witli a draw of -1^ in., and ran{j[ti in 
i*a])acitN' I'roiii II in. f 1'2 in. lo IH in. | *JH in., iJu^ ,^on(Mitl 
constrin'iion heinj^ niniilai'. 

Obloii;.'; luacliincM a,r(\ iuad(M>r M(|iia,ro Ivpe, but ai(^ Hiip- 
])ortod on (wo \i'i'H or ^itandill•dtH, on<* a( ciudi end, wil-ll 
IJio yoke (bipU('ii((ul o\tu- a,nd williin cacli f^(,a,nda.rd, t'.ou- 
nectcd with a, luuitra,! nbal'l, a,iid opiMaiiul by a Hin^^lt' 
(•ra,nK ni one »iid. 'Tboy luuc lb(^ .saiiu^ draw — -1r in. — ■ 
and ilu\v ouibi'acc^ pailcriiM IVoiu li? in. to '10 in. in width 
and IVoni '21 in. to IS in. in lenf^th, and la/rj^^tw to ordoi'. 

'IMu^ franu^s of all Hipiaic^ or rcctaMi^jjidar nnndiinen aro 
It'tt open at tlic «wi(b^, tliei-(d)y p(^rniittin|.^ tho iihc of 
pattoi-ns whicli ai(^ connidiu'a.bly lon^or tliaii the IVamo 
of tlit^ iiiacliiiK^ Tht^ Htrippin«j; plato Boilin;^ iiptm tho top 
of tlh^ fiaiiK^ is not iiinitiul to any partit'uhir ni/itt, ho that 
a, wido ran^o in nizoH oi" boxen is ptUMuitttHl. 

Tlio Cort^^oing form a ida,BH of inachineH whi(di are eoiu- 
pa.ra,iiv(dy li|^ht, liav(^ but one cranKshaft, a,nd with tlie 
t^xeeption just iianuMi lia.NC sliallow draws a,n»l hi^h 
tal)loH, and are a,dapt(^d to work of snuill and iiKMhiini 
dimennionH. 

Tliert^ is a.noth(u- la.r^o tdass lia.vin^ e]ia,ractiu"iHtie.B of 
an o})positt» eharaeter, btun;^ *' h(uivy," a,nd snita,bly d(i- 
signod h)r heavy work (Fij.;. '201, IMalo IX). Thest* ilhis- 
tra,t(^ a. nundiiiu^ in whieh a. wood(U) )>a.tt(U'n is niounttul 
with a, wood(Ui stripping phlt{^ a, method suitable for oc- 
caHional worlv. 



EXAMPLES OF MOULDING MACHINES 201 

These machines consist of single heavy castings for 
the main frame, standing upon legs at each corner. The 
frame is rigidly designed, which is essential in all mould- 
ing machines. Want of rigidity, causing the pattern to 
swing, and the moulding box to register imperfectly, has 
been the cause of the inefficiency of some moulding ma- 
chines. The "heavy" machines are square, oblong, or 
round, but the yoke which raises and lowers the pattern 
or patterns is operated by two parallel crankshafts and 
four guideways, or six in some of the longer machines. 
In these, too, the yoke upon which the patterns are 
mounted is a second single large casting. The yokes slide 
in guideways on the inside faces near the ends of the 
parallel sides of the main frames, on the top edges of 
which the stripping plate frame is mounted. Long bear- 
ings are cast in each corner of the main frame, close to 
the legs, and in these bearings are fitted t^vo heavy par- 
allel shafts. Upon each end of each of these shafts, set- 
ting close to the bearings, is keyed a double-ended crank ; 
in the upper ends of these cranks are pins upon which 
are journalled heavy pitmans, the upper ends of the pit- 
mans being journalled on pins riveted into the corners 
of the yoke. In each one of the lower ends of the four 
pitmans are the eccentric adjusting bushings described on 
p. 289 in connection with the small machines. The lower 
ends of the double-ended cranks carry cross connections 
to the lower ends of the cranks on the opposite shafts. 
The two sets of cranks at the opposite ends of the machines 
are at right angles with each other, thereby transmitting 
a perfect rotary motion from one shaft to the other. The 
end of one of the shafts is extended, and carries a lever 
by which the pattern is lowered and raised. A special 
feature is the coiled compression springs, two or more in 



292 PRACTICAL IRON FOUNDING 

number, by which the weight of the yoke and its burden 
is counterbalanced, so that patterns are drawn and raised 
easily. Springs of different strengths can be substituted 
in the sockets provided for them, to permit of exact ad- 
justments for patterns of different weights. 

Square machines of this class are ))uilt in dimensions 
ranging from 18 in. upwards to 60 in. wide and 120 in. 
long, with draws of from (3 in. to 8 in. They are built low 
to take deep flasks. Eound machines are also made with 
double shafts, with deep draws, in capacities ranging 
from 24 in. up to large sizes; GO in. is a large standard 
size, but larger ones are built when required. 



^^ 




Fig. 202. — Babbitt-lined Steipping Plates. 

The babbitt lining of the stripping plates in Fig. 202 
will be observed. The practice of using stripping plates 
is generally open to the objection of being costly, when 
the openings are tooled or filed to make a close fit with 
the bounding edges of the patterns. The babbitt system 
dispenses with this labour in the following way (the only 
exception is circular openings which can be turned 
readily) : 

The stripping plate is cast with an opening about | in. 
larger all round than the patterns. Its upper edge is 
recessed to a width of } in. and depth of {j in., and small 
holes are drilled at distances of about 2 iw- apart, into 
which wire nails are driven, leaving the heads about f V in. 
below the intended surface of the babbitt. When the 



FX AMPLE S OF MOULVTNG MACHINES 29?> 

pattern plate is placed on the machine, with the stripping 
plate surrounding it, asbestos string is laid around the 
pattern, and between the opening in the stripping plate 
and the backing or filling-down thickness pieces on the 
pattern joint. A layer of putty is laid round to form a 
trough. All is then warmed, and babbitt is poured in 
around the pattern, filling up the space. Before this has 
quite cooled, the operating lever is pulled, and the pattern 
drawn dow^n through the babbitt. The surplus is then 
cut away from the surface of the stripping plate. If the 
babbitt is found to make too tight a fit around the pattern, 
it is trimmed off until the pattern moves through freely. 
From 50,000 to 150,000 moulds can be made before a 
plate requires to be re-babbitted. By the adoption of this 
cheap and ready way the objection to stripping plates no 
longer holds good. 

In fitting these up, a single plate is thus prepared 
before the second is taken in hand. The second stage is 
as follows: 

Pattern plates and stripping plates are prepared for 
the complementary portion similarly to the first, and 
placed on a moulding machine adjacent, but without as 
yet having dowell holes drilled, or the babbitting done. 
But the pin holes are drilled in the 'lugs, and so the 
stripping plate first formed is taken from its machine 
and turned over and placed on the second stripping 
plate — located by the pins. The first stripping plate thus 
locates the position of the second part, which is now, 
therefore, dowelled in place, and the stripping plate No. 1 
put back on its own machine. The plate No. 2 is now 
babbitted round its portion of the pattern. Two pat- 
tern plates are thus prepared with strippers, to mould 
on separate machines for cope and drag respectively, 



294 PRACTICAL IBON FOUNDING 

and which will match perfectl}^ when the moulds are 
closed. 

The question often arises about making provision for 
moulds with irregular joint faces. Generally the method 
adopted is to cast pattern and plates in one, in a mould 
rammed originally with cope and drag face to face, and 
then separated by the intended thickness of the plate, 
and poured, after a suitable frame has been rammed 
around the mould. In the Pridmore system this is 
avoided by fastening pieces on one plate to stand up and 
come to the raised pattern joint, and to cast pockets in 
the other plate which are approximately the reverse of 
the raising pieces, and deeper. Nails are driven into holes 
drilled about f in. apart over the surface. The plates are 
then placed together and babbitt poured in, so forming 
an exact reverse. 

Rockover Machines. — One of these is shown at the left- 
hand side of Fig. 197, Plate IX. These are used for pat- 
terns in which there is sufficient draught to permit of the 
lowering of the mould from the pattern, assisted frequently 
by a vibrator rapping action. Often they are used in con- 
junction with a stripper plate machine making one portion 
of the mould. The action of the machine is as follows : The 
pattern plate, being covered with its flask, is rammed by 
hand when carried on one side of the machine. The 
superfluous sand is strickled off and a bottom board laid 
on the surface and clamped. Then the plate with its 
flask and board is rocked over on its pivots to the other 
side of the centre of the machine, and the bottom board 
deposited on a stand by means of a lever, the labour 
being rendered easy by the counterbalancing action of 
coiled springs. The mould is dropped from the pattern 
and the latter is returned to its original position to be 



EXAMPLES OF MOULDING MACHINES 295 

re-rammed. The varying depths of boxes are provided for 
by adjustments in the height of the stand. Some machines 
have provisions for self adjustments by means of four 
depressible pins to accommodate unevennesses in bottom 
boards and differences in thickness of sand. 

Portable Machines. — The Farwell moulding machines, 
manufactured by the Adams Companj^ of Dubuque, Iowa, 
are built in two broad types to accommodate work lifted 
with or without stripping plates, and in both fixed and 
portable designs, and some have turret heads for multiple 
and other moulding. All the Farwell machines are of 
the presser type, and are all hand operated. That is, no 
hand ramming is done, but the moulds are pressed, and 
the patterns delivered by hand levers. 

The general construction of the ordinary machine is 
as follows (Fig. 203, Plate X): Two standards support 
the superstructure. In the fixed machines these terminate 
in feet, to be bolted down upon timbers. In the portable 
shown, they are divided and spread out to receive the pins 
upon which plain wheels run. On the top of the stand- 
ards a longitudinal is bolted, carrying a table consisting 
of crossbars, or an open frame upon which the cleats or 
battens of the bottom board rest. The table is a rigid 
fixture. Above is the presser head — a planed casting 
carried at the ends of pitmans which are screwed along 
for a considerable length from the ends to permit of a 
wide range of adjustment of the presser head for height. 
The head can be thrown back out of the way, or brought 
into a horizontal position over the table and mould by 
the left hand. Then the lever to the right is pulled 
over, the attendant pressing his weight on it, so com- 
pressing the mould. The lever is in the horizontal posi- 
tion when the man's greatest effort is being exercised 



296 PRACTICAL IBON FOUNDING 

upon it, which is more favourable for obtaining the 
maximum result than a vertical or nearl}^ vertical one 
would be. 

This is a simple machine — termed the mouldinfi press 
— designed for work that requires no stripper plate. In 
this, as in others having no turn-over table, the cope and 
drag are pressed b}^ the turning over method, or else 
rammed simultaneous!}^ or independent of each other on 
the same or on separate machines. The operation of 
moulding is briefly this: 

Taking first a pattern requiring a plain top : A match^ 
which may be either a bottom hoard, as we should call it, 
or an oddside, is placed with its pattern or patterns in 
position on the table. The drag or bottom box is laid 
over it. Facing, and then box-filling sand are riddled and 
shovelled in and struck off level. A bottom board used 
for pressing is laid on the sand. One movement of the 
lever brings the top forward and presses the mould. The 
drag is now turned over on the table, occupying ap- 
proximately the same position centrally; the match is 
removed and put aside, leaving the pattern or patterns 
embedded. Parting sand is strewn and the cope laid in 
place, facing sand riddled in, followed by the box tilling, 
and strickled oft', a presser board laid on, which is 
identical with the bottom board in function and in shape, 
with a trifling difference in the cleats or battens, which 
are hollowed out at the sides so as to be easily grasped. 
This completes the moulding. 

The sprue cutting, the rapping, and lifting out of the 
pattern are all done by hand, as in ordinary work, so 
that the saving of time by the machine is due to the 
consolidation of the sand by the presser instead of by 
hand. The precautions adopted to ensure the proper 



EXAMPLES OF MOULDING MACHINES 297 

degree of pressure over all areas will be noted presentl}^ 
and also the withdrawal of deep patterns used with a 
stripper plate. 

In the plain moulding press to which these rempa-ks 
have reference patterns are also used, the halves or por- 
tions of which go on opposite sides of one plate. In these 
cases the plan adopted is this: the operation proceeds as 
in the previous case until the drag part is laid upon the 
bottom board and filled with sand over the pattern. In- 
stead, now, of pressing the board down, the drag part 
with the board is turned over and the cope laid on and 
filled, and the presser board laid in position. Thepresser 
head is now pulled down on the presser board, and the 
cope and drag sand are thus pressed at once between the 
top and the bottom boards. 

The Farwell universal moulding machine, Fig. 204, 
Plate X, is more complete than the moulding press. It 
can be used either for shallow patterns, or for deep ones, 
with a stripping plate, and the lift is mechanical. In the 
choice of fixed or portable mounting it is similar to that 
just described. But the universal machine is fitted with 
mechanism for lifting the pattern or patterns from above 
the stationary table. The patterns are mounted on a 
movable table, which is supported by a long slide of 
hexagonal section, with provision for taking up wear. 
The machine combines a common moulding press, with 
a stripping plate, so that either can be used at will. The 
construction is this: 

For moulding with stripping plates, the patterns are 
secured to one side of a board or plate, which is sup- 
ported a little way above the stationary press table. Only 
one side of the plate is utilized, because the table is not of 
the turn-over type. Cope and drag are therefore rammed 



298 PBACTICAL IBON FOZTNBING 

on different machines, or on a long machine capable 
of dealing with both boxes side by side at one operation. 
The pattern plate is fitted with tabes near the edges, 
through which loose studs pass and rest upon the 
movable table, termed the lift table. When a lever at the 
side of the machine — the lift lever — within reach of the 
operator's left hand, is raised, these studs engage with 
the edge of the flask and lift the mould off the pattern 
plate. The sand is loosened during the lift by the right 
hand of the attendant, who strikes a rapping bar hori- 
zontally between two projections. The box is then taken 
off and laid where required for coring or pouring. This 
is an arrangement suitable for a large volume of work 
which is either shallow, or, if deep, well tapered, or of 
circular section. The lift is truly vertical, while the rap- 
ping given is as efficient as that imparted in a common 
mould, but less in amount — less being necessary because 
the machine lifts perfectly vertical. 

When deep work with little or no taper, which requires 
a stripping plate, is to be moulded, the pattern plate or 
frame rests upon the stationary press table. The strip- 
ping plate lies on the pattern plate. Three or four studs 
attached to the stripping plate come down and rest upon 
the lift table. They engage with guides on the pattern 
plate, and control the vertical movement of the stripping 
plate. By raising the lift lever both the stripping plate 
and mould are lifted off the pattern, after which they 
are taken away. 

This is a concise account of these machines, without 
dwelling much on minute details. Some of these must 
now be noted, and the first matter which a moulder 
would like to be informed about is the pressing opera- 
tion, by which hand ramming is wholly dispensed with. 



EXAMPLES OF MOULDING MACHINES 299 

In shallow work the Farwell press simply utilizes the 
presser head coming down on the plain presser board for 
the consolidation of the sand. But in deeper patterns 
two further devices are utilized. One is peinijig, the 
equivalent of our pegging of sand down the deeper sides 
of patterns before ramming over the upper surfaces; 
the other is the device of cutting out the presser board to 
the approximate outlines of the patterns to be rammed. 

Peining is done by tacking a strip of wood of about 
f in. square on the faces of both bottom and presser 
boards, close alongside the edges. These, of course, being 
thrust into the mould before the flat portion of the 
board comes into operation, consolidate the sand firmly 
round the edges of the pattern and against the box sides 
adjacent, just as would be done by the moulder's pegging 
rammer. 

The presser head, which is cut to conform to the shape 
of the patterns, is attached to the presser top of the 
machine. The expense of cutting it out is not so objec- 
tionable as might appear, It is a question of number of 
moulds wanted. One would hardly cut it for a few 
moulds, but it would generally pay for a score or two, 
while when the cost is distributed over hundreds it is a 
mere trifle on each. The expense is not so great as that 
of cutting out half a core box, which it resembles, because 
the accuracy necessary in a core box is not required for 
pressing the sand. 

When the Adams Company plate patterns they use 
saw-blade steel plates ^ in. thick, which are straight- 
ened, ground, and polished on one side. As the patterns 
are only mounted on one side, the plates are stiffened by 
riveting three bars \ in. by 1^ in. on the underside, and 
running in the longitudinal direction. The patterns are 



300 PRACTICAL LEON FOUNDING 

of metal, secured to the polished face. Sockets of gas- 
pipe, previously mentioned, are fitted near the edges of 
the plates to receive the loose pins, which have been 
described as coming down and resting on the lift table 
of the machine. When patterns of wood are used, tliey 
are secured to one side of a board. 

As the pattern plate stands up on its pins away from 
the lift table, curved patterns and curved stripping plates 
are easily fitted. 

For more rapid production, pattern plates are dupli- 
cated on the same machine, so that one man will ram 
cope and drag simultaneously. The pattern or patterns 
are set by centre lines to right and left of the common 
centre dividing the cope from the drag portion; or two 
machines are employed. In plain cored work a boy may 
then set the cores. 

j\foulding boxes are not necessarily made to fit these 
machines, as they simply lie upon the table, and the 
stripping plates, when such are used, can be adapted to 
the ])oxes. But there are certain relations between boxes 
and bottom or presser boards which should be regarded 
if the best economy is studied. The boards and boxes and 
the depths of patterns should be mutually related. As 
the bottom and presser boards enter the drag and cope 
to press the sand, f in. is the allowance in depth made 
for this, so that whatever the depth of flasks required 
for hand moulding, -f in. must be added for machine 
moulding. The differences in depth of flasks for different 
jobs are recommended to be made in these boards and 
in the match. Thus, taking 91 in. as a convenient 
distance between the table and top, when the pressing 
lever is about horizontal the machine should be adjusted 
to that, and shallower flasks fitted by increasing the 



EXAMPLES OF MOULDING MACHINES 301 

thickness of the cleats of the boards and the match. 
The bottom and presser boards are made smaller by 
I in. than the inside of the Hasks, so that they enter 
easily when pressed. They are of white pine IJ in. and 
1^ in. thick respectively, with battens 4 in. by 1} in. The 
battens of the top or presser board are hollowed out for 
the hands. 

Ordinary flasks of wood, or iron, or snap flasks are em- 
ployed. A cherry snap flask is made by the Adams Com- 
l^any, protected with iron on the top edges, grooved in- 
side to hold the sand, with pins of triangular section. 

A special Farwell machine is fitted with a turret head 
for the production of multiple moulds. It is an ordinary 
moulding press fitted with a head having two portions. 
On one portion a pattern plate containing a part of a 
mould is attached. On the other a peining or pegging 
frame is secured, the object of which, as previously ex- 
plained, is to consolidate the sand around the edges 
preparatory to the surface pressing. A flask filled with 
loose sand is laid on the table over the second portion of 
the pattern, and the peining frame brought down upon 
it. The surplus sand is strickled off and a thin layer of 
facing sand riddled over. Into this the pattern or the 
patterns on the turret are pressed, so forming a portion 
of a mould on each face of the sand mould. The first sec- 
tion is placed on the floor, and the others are piled on 
as made until completed. 

Fig. 205, Plate XI, shows a hand machine with non- 
turn-over table, and hinged presser-head, by the Berk- 
shire Manufacturing Company, of Cleveland, Ohio. The 
pressure is intensified by toggle levers. The pattern- 
plate is lifted from the drag, and the cope from the plate 
simultaneously by the movement of the lever seen below, 



302 PRACTICAL IRON FOUNDING 

the guidance taking place through four posts, a pneu- 
matic vibrator put into action by the knee assisting the 
delivery. The posts are attached to a frame which per- 
mits of adjusting their position to suit different pattern 
plates and boxes. The frame is operated by gears run- 
ning inside racks ensuring a straight lift, and the frame 
is also coerced in guides. Canvas guards enclose the 
vital parts. Copes and drags are rammed on the two 
sides of a plate, or on different machines. 

Tabor Machines. — The Tabor Manufacturing Company, 
of Philadelphia, make moulding machines to suit the 
varied classes of work required in foundries, some for 
stripping plates, some without, some for hand, and others 
for power ramming. Improvements are effected from time 
to time in the standard types, besides which special 
adaptations are constantly being made to suit special 
classes of work and existing moulding boxes. For these 
reasons it is not possible to take any one machine and 
describe it as being a Tabor. It would only be correct to 
say so respecting certain main elements in the design and 
some fundamental details. For this reason the firm is un- 
willing to have these machines described in any other 
than a general way, lest an idea should be conveyed that 
the illustration which might be given would represent a 
hard-and-fast design. We shall therefore only attempt 
to deal with the broad features which characterize these 
machines, illustrating one only, the 10-inch power 
squeezer for light work (Fig. 206, Plate XI). 

An observer would notice the vibrating action through 
which the pattern is loosened from the sand previous to 
its withdrawal, as being one of the cardinal features of 
many of the Tabor machines. It does not dispense with 
other devices, but it renders possible a good deal of work 



EXAMPLES OF MOULDING MACHINES 303 

which could not be accomplished by any other means, 
short of an expensive rig-up of stripping plates. The 
vibrator is a plunger from f in. to 2 in. diameter, ac- 
cording to requirements, which plays to and fro under 
the action of compressed air at a pressure of about 75 lb. 
per square inch, brought through a hose and actuated 
by the attendant pushing a valve. The vibrator moves 
to and fro several thousand times in a minute, and 
strikes against hardened anvils at each end of its cylinder. 
The result is that the pattern is shaken at an extremely 
rapid rate with a much slighter degree of movement than 
that which is imparted in ordinary rapping. It is so 
slight that when a deep pattern is returned into the 
sand, it has to be rapped again before it can be with- 
drawn. The result is therefore the same as though an 
expensive stripping plate were used. In the vibrator 
frame machines, one vibrator frame is fitted to any single 
machine, but to that any patterns, large or small, are 
readily fitted. The frame is an open one, slotted around 
its inner edges to receive extensions from the pattern 
placed within the frame. The extensions, being thin, are 
sometimes attached to gates, and frequently to core 
prints. In the latter case they are utilized also as vents 
going to the outside of the mould. Pins or screws connect 
the extension pieces to the vibrator frame. Some firms 
keep a standard or jig frame in the pattern shop to 
facilitate the fitting of any patterns to the vibrator 
within the capacity of the machine. 

The vibrator frame is guided in flasks by three-cornered 
pins, one at each end. These fit within the pins of the 
drag, which are also, of course, of triangular forui, while 
triangular guides on the cope fit outside these pins. 

We will now observe the operation of the Tabor 



304 PRACTICAL IRON FOUNDING 

machine (Fig. 200, Plate XI), and the first thing to note 
is the absence of the turn-over table which is embodied in 
numerous machines. This is an advantage in one respect, 
that unjointed patterns ma}^ be employed, which is im- 
practicable on turn-over tables. No special fitting of boxes 
to plates or tables is required, but the boxes fit to the 
vibrator frames and to each other. Being able to take 
any unjointed pattern of wood or metal and fit it within 
the vibrator frame, Fig. 207, Plate XII, and mould it by 
turning or rolling it over, is a great point in favour of a 
machine. It would, of course, weigh more in the case of 
moulds of which a small number only were wanted than 
in the case of those where hundreds or thousands were 
required, because the latter will pay for the jointing of 
patterns and their careful fitting. A^nother point in favour 
of the moulding of unjointed patterns is that it is easier 
to ensure absence of overlap and fin than when they are 
jointed, especially when put on separate plates. Even 
though they match originally, the wear and tear of 
machines, of pattern, and of stripping plates, when such 
are used, tends to increasing departure from perfect joint- 
ing of moulds. 

Having the pattern mounted within the vibrator frame, 
the sequence of operations is as follows: The joint board 
is laid upon the table, and the pattern or patterns con- 
tained within the vibrator frame are placed on it. The 
drag or bottom box is laid on, fitting it by its hollow 
vee-shaped pins over the pins at the ends of the vibrator 
frame. Sand is shovelled into the box and struck off 
level, and a bottom board with thick cleats or battens 
laid on the sand. Above this there is a presser head, 
hitherto thrown back clear of the work by hinged rods at 
the sides, but now pulled forward until the presser board 



PLATE Xiy 









^P" 


-*$'^^^ 


" i ,' **" 


mt - » 






f 



213 



^'''-l'- •■^*-' { Farina p. 3*4 

Fig. 213. — Patterns, Core Boxes, and Multiple Castings. 
The London Emery Works Co. 



EXAMPLES OF MOULDING MACHINES 305 

stands horizontally, in which position it is arrested by 
stops. There is a three-way cock at the side of the 
machine by which the attendant admits compressed air 
at from 60 lb. to 80 lb. pressure, into the inverted 
cylinder in the base of the machine, forcing the match 
board, drag, and bottom board up against the presser 
head once, twice, or thrice, as happens to be most suit- 
able for the work in hand. This completes the first 
stage. 

The ramming head is next thrown backwards, and the 
drag, with its joint board, turned over, w^ith the vibrator 
frame between them. The match is then lifted off, 
leaving the joint face open to receive the top box, which 
is fitted over the pins of the bottom box. Parting sand is 
dusted over the face, moulding sand thrown on, a board 
placed over, the presser head pulled forward, the cock 
turned, and the mould pressed up against the head. 
This completes the second stage. 

Delivery of the pattern is effected as follows : The cope 
is first lifted by hand. As it is about to be lifted the at- 
tendant pushes a hinged pad in front of the machine 
with his left knee, which admits air to the vibrator, and 
during its action he lifts the cope off. To withdraw the 
patterns from the bottom box the vibrator is started, and 
the frame is lifted by the handles at the ends. 

On first thought we might be disposed to think that 
one of the chief advantages of a moulding machine, that 
of a perfectly vertical lift, is sacrificed. The importance of 
this is greater in the top than in the bottom. But the 
drag pin is sufficiently long to ensure perfect control of 
the lift in moulds of medium depth at least, so that un- 
less in work which is obviously suitable for stripper 
plates the supposed objection does not apply, and in 



306 PRACTICAL IRON FOUNDING 

some deep stripper-plate work the vibrator is included 
with advantage. 

Tabor machines are fitted with stripping plates of sheet 
metal when required, and with the devices termed stools. 
The sheet metal covers the entire surface of the machine, 
except, of course, where it is cut out round the patterns. 
The sheet is supported by the pattern plate during ram- 
ming, and the stools carry its edges during the with- 
drawal of the pattern. The stools in this case are loose 
cylinders of metal which fit in round holes bored through 
the pattern plate. The surfaces of their upper ends 
come flush with 'the surface of the plate, and their lower 
ends rest on a stool plate. This last is supported rigidly 
by means of brackets from the frame which carries the 
moulding boxes, so that it has the same upward motion 
as the boxes, and the upper ends of the stools therefore 
remain in contact with the sand of the mould until it is 
lifted from the machine. * 

Machines made by the Baden Engineering Works of 
Durlach embrace nearly every type. Some are of small 
size; others are of very large dimensions; they in- 
clude numerous designs and systems, embracing hand, 
hydraulic, and pneumatic operation, turn-over plates, 
and fixed plates, pulley moulding, and other special 
machines for pipes, firebars, toothed wheels, etc. 

The simplest type of hand machine made is of very 
plain design. It consists of a table supported on four 
stiff legs, which bring it to a height suitable for ramming 
by a man standing upright. The pattern plate is fastened 
on the table, and the moulding box placed over it, fitting 
by its pins thereto. The sand is rammed and strickled 
level, and the box lifted off the pattern truly by a pedal 
lever arrangement, which lifts a crosshead underneath. 



EXAMPLES OF MOULDING MACHINES 307 

when four rods at each corner that pass through the 
pattern plate push up the box clear of the pins. These 
machines are made for boxes that range from 12 in. to 
24 in. square, and are intended to be used in pairs for 
top and bottom boxes respectively. 

Another single-lift machine without a turn-over plate is 
designed for boxes of larger dimensions. Instead of the 
box being lifted off, which could not be readily done be- 
cause of its weight and size, the pattern is drawn down- 
wards by means of a lever actuated by a screw of quick 
pitch, the weight of the pattern table being counter- 
balanced. The box is left supported on four projections 
on the frame. This machine is suitable for patterns of 
no great depth. In deep work it is better to lift the 
pattern upwards out of the sand than to draw it down- 
wards. 

Other hand moulding machines by this firm have a 
turn-over plate fitted, the pattern parts being fastened on 
opposite sides of it; patterns of plaster, white metal, or 
other materials being used equally well with those of 
wood or metal. When preparing these pattern plates for 
foundries which deal less in repetitive work than in small 
numbers of castings, the plates are made with a large 
number of holes which are fitted with corks when not in 
use. Holes can be selected from these to suit various 
patterns, and the remainder left with the corks in. The 
method of fastening is by means of tubes, screws from 
one half the pattern entering into holes in the tubes in the 
other half, ensuring the correct placing of the two portions 
through the intervening plate. The halves of the mould- 
ing boxes are placed on opposite sides of the plate, their 
positions being fixed by two pins which pass through the 
plate, and stand out on opposite sides, and to which the 



808 



PRACTICAL Ih'ON FOUNDING 



box lugs are secured by wedges. Or, the pins form apart 
of the box and pass through the plate. These machines 
are made for work of medium dimensions, taking boxes 
ranging from !(> in. by VI in. to 40 in. by 82 in. The 




Fig. 208. — Turn-over Table Machine. 
Front Elevation. 



depth of each half-box varies from 10 in. to 12 in., a good 
depth for machine moulding; but in this case, of course, 
the pattern plate is lifted from each box part. 

In another hand machine of larger dimensions, in 
which the design of a turn-over table is retained, the 



EXAMPLES OF MOULDING MACHINES 309 




1 \///M/^///}^^/Z^^ 
L- . _^ 




moulding box is supported on a carriage running on 
wheels, and is lifted up to the pattern plate and lowered 
therefrom by hydraulic power. A piston underneath does 
the lifting and lowering, and as no great power is re- 
quired, a hand pump can 
be used in the absence of 
a regular hydraulic plant. 
Boxes of larger dimensions 
are used on this machine, 
ranging up to 172 in. by 
16 in., with a depth of 12 in. 
In other turn-over types 
of machines, instead of 
hand -ramming, provision 
is made for compressing 
the sand. In one of these 
toggle levers are employed 
to permit of the exercise 
of increased force as the 
depth of sand increases. 
This machine is illustrated 
by the drawings Figs. 208 
and 209 in part elevations 
and sections. TwoA-shaped 
frames A, A, sustain the 

mechanism. Two cross ^^^ 209.-Tuen.ovee Table 
stretchers B, C connect the Machine. Vertical Section. 
frames. D, E are the levers 

which form the toggle — straightening out as the pressure 
on the mould is increased. They are pivoted in bosses in 
C above, and in B below, and are actuated by the hand 
lever / which turns the pinion P engaging in the quad- 
rant rack it on the lever D. The table F is thus pressed 




:U(^ /•/,• i('/7(M/. //.'('.v I'ot \ nixc 

upwards }i>;!vinsi ilu> uuMiKliMj; boxt^s /v, /\ . in opposition 
lo llu^ iTt>sslu>!hl (t. whu'li IS I'onut^i'toii l)\ r*uls //. // to 
{\\c bottom o( {\\c si}uui}irtls. (I is [^ivoUnl 1>n llio roils, 
niul call bi^ swim;; bark on[ ol lbi> way (o piaiuit (>! Ibo 
ii\sorti(Mt aiiil iianoval iW" boxt^s. 

'lMu> (urn ovrr tabK> is s(HM» at J, \\\\\\ boxes ai l\ , K. 
J oarrii^s iiUornuHliati" bKn-ks. tbt> t'imrtii>n of \Nbii'b is to 
riH'rivi* (hi^ pins (ov {\\c I'oxiv;. /, is tb(> [»rossi'r boa.r(l, 
anil M a Ku^st> frnino into N\liii'b i\\o surplus sa.nil is 
shov(>ll(il, ol" a (bii'knt^ss about 0(|nal t(> (lu^ roilin'tion 
riVoi'loil bv tlio I'oinpri^ssion. Tlu* box parts art* stu'iiroil 
to tlu* lablo wbilo boiii;', tiiiiuul o\ov b\ clainps. i>no of 
wbii'li is si'tMi bi\»kon otT at A. I'iacb lialf is fitted anil 
i-iMnpit^ssoil si>|»a.rn.ttdv, Inrnoil o\or, (bo I'ottars knoi-kiul 
bai'k. tbo bi>x pari ri>i'(M\o(l bv (bi\ labK* /•', ami tin* pat- 
tiM'ii plati* lifttul from olT it bv tlio i'oiintor\voi{;lili*d loV(>r 
(), tbo iTossbouil (i IxMii", o\' I'oiirso tliro\vi\ bai'k out of 
tbo \va\. Tbo top ami bottom parts {){ tbo moiiM a.ri^ 
(bus pii>p;irrd altornalolv o\\ ono macbino. Tbo soipioiico 
is as tollows: 

A box part is iirfd fasionoil on tuu'b siili> o{ tlio iuru- 
ovtM" [)lati*on Nvbii'b tbo pattiMais ivvo sot, ami tbo bottom 
box boin^ first turntul upwards, is lillod witb fafinj;' and 
coarso sands up to tbo lop of tbo idainpiuj; frami> ,1/, tbo 
])r(>ssin«» bi>ard /, is put on, tin* brad a broui'jit o\or it, 
and till' tox.pjo lo\or / piillod. Tbo turn o\or plato is nt^.xt 
rovorsod, brint^iiif; Ibo box just prtvssod down on Ibo 
labK'. and tbo otbor or ti>p box is Iroatoil similarlv. Tlu-n 
(bo \\idj;os of tbo bot(i)m box aro knorkiul bai'k, and tlu^ 
[)lato liftod and tbo box drawn forward on tlu> ta.blo. 
Tlu^ plato is Ibon turnod ovor for anotbor box })a.rt. 

Hosidos tboso tbon^ aro lar^^o numbors o^ marbinos tbat 
aro oporalod bydraulically, ranging fit>m soim* oH vory 



312 PBACTICAL IB ON FOUNDING 

simple type for small castings, and attended by boys, to 
others of very large dimensions and of more or less com- 
plexity. The advantages of the application of hydraulic 
power to this class of ^york are indisputable. The stand- 
ard pressures adopted are 750 lb. to the square inch for 
moulds for iron castings, and 1,5001b. for those of steel 
and other castings. As the sizes of boxes increase, the 
weight of the box, with that of the enclosed sand, taxes 
the muscles severely in hand machines, in spite of long 
levers and counterweighting. The application of power 
does away with this exertion, and permits of the use of 
machines of any dimensions adapted to heavy classes of 
work that could not be economically put on hand-oper- 
ated machines. The hand machines, with turn-over 
plates just now described, are also made after the same 
model for hydraulic power, a piston beneath pressing the 
moulds upwards between it and the crosshead at the top. 
Machines of this type range from a capacity for boxes 
measuring from 16 in. by 12 in. to 172 in. by 16 in. 

Another class of hydraulic machine is double. Fig. 210, 
without a turn-over plate, the object being to have two men 
working on top and bottom of a mould with a central 
presser. The moulding tables travel to and from the press. 
The moulds are prepared on these tables, and brought 
under the press in turn. The pattern plate is removed 
downwards from the mould after pressing, leaving the 
moulding box on two side bars. The largest machines are 
fitted with a light hydraulic crane, to place the boxes on 
the closing-up table. In the largest of these types, boxes 
up to 150 in. by 16 in. are handled. 

The Figs. 211, Plate XIII, show a group of machines by 
the London Emery Works Company, for moulding Hat 
and shallow castings, such as gas, water, or electric 



EXAMPLES OF MOULDING MACHINES 313 

light fittings, stove and grate parts. The two machines, 
seen at the right hand, each comprise a pattern plate, 
mounted on a hydraulic ram enclosed in a cast iron case 
to prevent the intrusion of sand and dirt. The rammer 
head is supported on pivoted links, and is swung back 
during the filling of the moulding-box with sand, and it 
can be adjusted to regulate the length of stroke, thus 
economizing power. The moulding-box is lifted off the 
pattern by four rods actuated by the lever seen in front. 
These rods must be flush with the pattern plate in their 
lowest position, and they can be adjusted to suit the 
various heights of pattern plates. 

It is advantageous to have two machines working to- 
gether as shown, one making the bottom and the other 
the top boxes, as the work can then be carried on con- 
tinuously, otherwise the patterns must be changed, or 
arranged on the reversible pattern-plate system. If re- 
quired, the machine can be constructed for extracting 
deep patterns through a stripping plate. Snap flasks can 
be used. Should an hydraulic plant be unavailable for 
any reason, the machine can be worked by hand without 
any alteration. At the left a hydraulic core machine is 
shown, completing the installation. 

Messrs. Bopp and Reuther, of Mannheim, make a 
speciality of hydraulic moulding machines of several 
types, comprising very advanced examples. 

A hydraulic machine with turn-over table is shown in 
vertical section in Fig. 212. The table A swings in trun- 
nions, which are clamped by the handles a, a when the 
table is set in its horizontal position. The trunnion bear- 
ings are in one with the sleeves B, B that slide in the up- 
rights, and the height of which is set by the collars h^ h 
clamped to the pillars. At the commencement of working. 



814 PRACTICAL IKON FOUNDING 

an empty balf-moulilingbox is set on the turn-over plate, 
and the other half on a wagon C that runs on rails. The 
upper box is tirst filled with sand, and the regulating- 
valve D operated, causing the ram to move upwards, 
pressing the sand in the box up against the presser 
head F. The latter is hinged, to be tlung aside during 
ramming. A pressing frame G, to confine the loose sand, 
is laid over the box, as is usual in such cases. Before 
taking ofi' the pressure, the two half-boxes are clamped 
together against the intervening plate, the clamps being 
shown at f, c. The regulating valve 7> is now released, 
allowing the ram to sink gently, and with it the plate A 
with the box parts, until their movement is arrested by 
the collars h, h. The plate is now turned over, bringing 
the rammed box underneath and the unrammed one up- 
wards. The latter is then filled with sand, and pressed 
as the other was. The clamps are next released and the 
ram lowered; the descent is arrested by the collars 6, h, 
and the second box sinks away from the pattern. The 
process is thus repeated, successive half boxes being 
rammed on opposite sides of the plate. 

It is customary in using these machines to press the 
pattern into the mould after blackening, as brass- 
founders do. Various presser heads can be made inter- 
changeable on the arms to suit moulds of difierent 
depths. These machines are made in a large range of di- 
mensions. With the hydraulic arrangement very heavy 
moulds can be handled with great facility. 

The question of fioor space often arises when the 
adoption of moulding machines is being considered. 
Even if the machines themselves do not occupy much 
room, much space is required for the finished moulds, 
the sand, and empty moulding boxes. The problem be- 



EXAMPLES OF MOULDING MACHINES 'S\6 

comes acute in proportion to the rapidity of action of the 
machine. One solution is the portable machine, p. 295. 
Another solution is that of multiple moulding. Machines 
are constructed by which a single half moulding box, after 
being pressed on both sides carries a mould. The half 




'^ 



"^ 



Fig, 212. — Hydraulic Machine with Turn-ovee Tablp:. 



boxes are then stacked on top of each other, a complete 
mould being formed at each joint, and the entire stack is 
poured through one gate. By stacking the boxes in this 
manner the difficulty of floor space is solved, but other 
important advantages result. Thus, as each half mould- 
ing box contains two half moulds, one half box suffices 
for each complete mould; and on reference to the illus- 



316 PRACTICAL IBON FOUNDING 

tration, Fig. 213, Plate XIV, it is shown that by using nine 
half boxes eight piles of castings are obtained. As only 
the upper half box in each stack contains an ingate, a 
considerable saving of metal is effected. Also, only half 
the quantity of sand is necessary for each mould. As, 
using ordinary machines, two half boxes are required for 
each complete mould, the capacity of the multiple machine 
is therefore nearly doubled. The illustration shows pat- 
tern plates, core plates, or boxes, some cores, and a pile of 
castings as poured. The machines used are practically 
identical with those shown in Fig. 211, Plate XIII. The 
moulding box is lifted off the pattern on four pins by the 
lever in front of the machine. The presser-head, how- 
ever, which carries underneath one-half the pattern, does 
not swing back, but is arranged to push back on rollers. 

The method of working is as follows: a moulding box 
is placed on the pattern plate, a sand frame placed on it 
and filled with sand. The presser-head with pattern plate 
is then drawn over and the box rammed in the usual 
manner. A half-mould is thus made on each side of the 
half box. After pushing the presser-head back, the 
moulding box is raised off the pattern plate on four 
pins by a lever in front of the machine. Continuing in 
this way one box after the other is made and stacked 
in lots of ten to twelve, the top one being weighted as 
usual. 

A machine designed for multiple moulding, by Messrs. 
Bopp and Eeuther, is shown in Figs. 214, 215, in which 
two half-moulds are made at one pressing. One half is 
done in the usual way by a half-pattern A, on a plate; 
the other half is by a frame B, which is pressed into the 
upper half of the moulding box C. The relations of the 
moulds and patterns plate before pressing are shown in 



EXAMPLES OF MOULDING MACHINES 817 

Fig. 214, and after pressing in Fig. 215. The method of 
operation is as follows: 

The box part C is carried upon a frame D, which is 
slid by means of sockets upon vertical guides. When set 




Fig. 214 Fig. 215. 

Machine for Multiple Moulding. 



thus in place, sufficient pressure is put on the ram E to 
bring the pattern and plate A into contact with the 
lower face of the box C. The latter is now filled with 
sand and the frame B laid upon it, the latter also being 
filled with sand. The water is turned on again, pressing 
the lower half-pattern into the box C, and the upper half 



318 



PRACTICAL IRON FOUNDING 



cH ri..HL-.^F^ 



i 



t 



into the frame B, after which the ram is lowered, leaving 
the mould complete with its ingate. It will be observed 
that the top half of the pattern is carried on a travelling 
wagon, which can be run aside when the sand is being 
shovelled into the boxes. A series of superimposed 
mould is shown in Fig. 216. 

The larger the number of moulding machines of a 
single type and size used in a foundry, the better chance 
is there to make economical arrangements in the depart- 
ment. In some English shops, a circus is used for load- 
ing and conveying away the boxes. 
It is an annular table suspended by 
rods from a central pillar, around 
which it is turned. In other cases 
a conveying table runs on rollers. 
In others, parallel rails are used, 
down which the boxes are slid away 
from the machines, and from which 
they are taken and laid to right 
and left on the floor. These are ad- 
juncts of the fixed machines. The 
use of portable machines is growing 
in the case of light machines. If a large number of 
power machines can be utilised, then the most elabor- 
ately designed plant results in the highest economies, 
and probably a hydraulic plant is the best on the 
whole to adopt. When many machines are fixed in a 
large system, the question of handling the sand and 
moulds offers far less difficulty than in the case of a 
few machines only. Not only does it pay to make me- 
chanical provision for taking away the finished moulds, 
but adequate arrangements can be made for conveying 
the sand and empty boxes to the machines. In a perfect 



m 



Ml 



Fig 



216. — Multiple 
Moulds. 



EXAMPLES OF MOULDING MACHINES 319 

system such as this, the men never leave the machmes, 
but the making of a mould is the work of several, begin- 
ning with the sand room, and ending at the metal pourer. 
Each machine operator receives his sand ready mixed, 
and boxes, rams the whole, or probably only half a mould, 
which is conveyed away to be cored by others, closed by 
others, and poured by another set of men. 

And further, in this entirely mechanical system, which 
is carried on with nearly military precision, other 
machines besides those used directly in moulding attain 
an importance beyond that which they possess in the 
general jobbing shop where a heterogeneous class of 
work is done. Coremaking machines are moulding 
machines of a special class, and the use of these is ex- 
tending. The fettling department is affected, for machine- 
moulded castings are, or should be, cleaner, more free 
from lumps and fins than hand-made ones, and the 
tumbling barrel and emery wheels are able to deal with 
these in quantity. 

Co7'e Making. — The making of cores by machines in- 
evitably follows the preparation of the moulds, or other- 
wise the coremakers could not keep pace with the output 
of the machines. For many years cores of circular and 
polygonal sections have been made by machines provided 
with pistons which push the cores out of the boxes end- 
wise, but these now constitute only a small section of the 
work done in coremaking machines. The largest of 
these, of which Fig. 217, Plate XV, is a typical ex- 
ample, resemble the hydraulic moulding machines, the 
difference consisting chiefly in the substitution of core- 
plates for the pattern-plates. In these cases the edges of 
the core-plates, or core-boxes strictly, are chamfered to 
cut away the sand and prevent it getting in the joints. 



320 PRACTICAL IRON FOUNDING 

This is shown very well in Figs. 218, 219, Plate XV, in 
which the plates are seen above and the cores moulded 
from them below. The output of Fig. 218, in which the 
core-plates measure 16 in. by 12 in., is 48 cores per hour 
when made on a hand machine. The output of Fig. 219 
with core-plates of the same size and using a hydraulic 
machine is 72 cores per hour with one man. Fig. 220 is 
an example of a coremaking machine of another kind, in 
which the halves are withdrawn laterally by means of a 
right- and left-hand screw. 

Withdrawal of Patterns. — Not the least interesting sec- 
tion of machine moulding, from the operative moulder's 
point of view, are the mechanical details of pattern 
moulding. In ordinary work we may say broadly that 
the pattern is either lifted from the mould, or the 
mould is lifted off those portions of the pattern which 
come in the top; and the pattern is self-contained — that 
is, it is not attached to or cast with any kind of plate. 
In machine moulding both lifts are common, either 
the pattern or the mould being lifted. But besides these, 
the pattern is just as often drawn downwards, leaving 
the mould above it ; or the mould is drawn down- 
wards, leaving the pattern above. Neither of these two 
last would be practicable in hand moulding, as they are 
in a machine where vertical movements are rigidly con- 
trolled ; and their practicability widens the range of use- 
fulness of the moulding machine. Either device has 
advantages over the other in certain classes of work. 
In the case of shallow patterns it makes no difference 
whether the box or pattern is lifted oft' the pattern, or 
the pattern drawn down from the box. In deep work it 
is better to lift the pattern and plate oft' the mould, or to 
lower the box away from the pattern. In either of the 




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EXAMPLES OF MOULDING MACHINES 321 

latter plans stripping plates must often be used to pre- 
vent the sand from breaking down. 

Machine moulding has developed into a highly-organ- 
ized system where machines and methods are correlated 
and interdependent. It has effected a revolution in some 
shops in costs, in labour, in many of the details of pattern 
work, and what it has accomplished in the few will be 




liClZD 



Fig. 220. — Core-making Machine, with Sand Bin. 



done in many ere long. It must be so as competition be- 
comes more severe. Already work is done by machines 
that would have been deemed impossible half-a-score of 
years since, and it would be unwise in the light of that 
advance and the promise of the future to attempt to set 
any limits to the capabilities of moulding machines, and 
the systems of which they form a part. 

Boxes. — It may be taken as a fact that many moulding 
boxes in the near future will be designed specially for one 

Y 



322 PB ACTIO AL IRON FOUNDING 

class of work only. To some extent this holds good now, 
just as it does in the case of large numbers of machine 
tools which are only seen in the shops in which they have 
been designed, if not built. Pulley moulding machines 
are a familiar example of special machines; so are car or 
railway-wagon wheel moulding machines, and machines 
for moulding firebars, others for radiator pipes, and for the 
vertical parts of radiators. In these, stripping plates are 
used, and power pressing, notwithstanding that the bars 
and ribs are deep, and the spaces both between bars and 
ribs are very narrow. The numbers required off pay for 
the cost of fitting up stripper plates and presser heads, 
and though the work is massive, the application of 
hydra.ulic power robs it of all excessive labour. Pipes 
are moulded by these up to 6 ft. in length, and firebars 
up to 60 in., and several firebars are moulded at once. 

Mechanical Pressing. — It has been made clear that me- 
chanical pressing cannot in all cases properly supersede 
the necessity for hand ramming. It is claimed for presser 
heads that the moulds are all pressed uniformly, and 
that therefore castings will all come out alike. But uni- 
form pressing is just what is not desirable in many 
moulds, because uniformity of pressure over the area of 
the head does not mean the same thing at different 
depths of irregular moulds. Besides wdiich, it is w^ell 
known that some portions of many moulds must be 
rammed harder than others. In proof of these facts, 
which are obvious to moulders, many of the most suc- 
cessful machines in use now are made for hand ram- 
ming. Power ramming has its place in foundries, but 
its utilities are limited to certain classes of work, or to 
work for which suitable dummy presses are cut. Many 
devices have been patented to facilitate the ramming by 



EXAMPLES OF MOULDING MACHINES 323 

power of deep patterns and irregularly shaped contours. 
They emphasise the fact that power ramming, except in 
plain, rather flat w'ork, is not successful, apart from the 
assistance derived from suitable devices. 

Jar-Ramming Machines. — The chief utilities of these 
machines (the latest type) lie in the ramming of deep 
moulds. They are not suitable for shallow ones unless 
an excess of sand is used. Depth is necessary to ensure 
consolidation of the sand, which is increased by the jar- 
ring from twenty-five to thirty per cent. The sand is 
denser at the bottom than at the top. The upper stratum is 
usually lightly rammed by hand after the jarring. A sand 
frame has to be used to confine the extra sand required 
for consolidation. No venting is required. The economies 
are enormous. The actual jarring does not occupy more 
than half a minute. A flask can be placed on the 
machine, jar-rammed, and removed in two minutes. A 
similar mould of moderate size if hand rammed would 
occupy from twenty minutes to half an hour. There is a 
vast future for these machines though they are little 
known at present. 

Figs. 221 and 222, Plate XVI, illustrate the Hermann 
jar-ramming machine constructed by the Pneumatic En- 
gineering Appliances Company, Limited, of Westminster, 
S.W. This is built both for stripping-plate work and for 
turn-over moulding, the latter being an arrangement 
which is removable, and not shown in the photograph. 
The parts of the jarring mechanism are enclosed in the 
cylinder seen at the base of the machine, to which air is 
admitted through a valve to effect the jarring. The 
mould is raised off the pattern by the pneumatic cylinders 
at the end, and the separation of pattern and mould can 
be effected either upwards or downwards as desired. A 



324 PB ACTIO AL IRON FOUNDING 

special feature of the machine is the oil-governing ar- 
rangement in which the cylinders for raising and lower- 
ing the pattern table and moulding box are governed 
perfectly, so preventing injurious shock. The oil tank is 
seen at the front in Fig. 222. The machine is set to 
strike about 120 blows a minute, and twenty-five to fifty 
jars are sufficient to set the sand in an ordinary mould. 

The action of the jarring machine may be understood 
by regarding it as composed of two essential elements, 
the jarring table which carries the pattern and mould, 
and the anvil. The table is lifted and dropped repeatedly 
and rapidly on the anvil. But in order to lessen the re- 
sulting shock the latter is cushioned, and is often also 
made to lift to meet the falling table. In the delicate 
relative adjustments of these two movements the effi- 
ciency of the machine lies. Hence, though the action of 
the jarring machine is simple, the details have to be 
worked out with care, because the jar or shock which is 
the efficient agent in the consolidation of the sand is 
also, if too severe, destructive to the machine, the flasks, 
the sand of the mould, and even to structures in the 
immediate vicinity. 

The weight of the table, the Hask, pattern, and sand, 
is lifted to a height which varies from say 2 in. to 3 in. on 
an average, and is then dropped on the anvil, the action 
being repeated perhaps thirty or forty times within the 
space of half a minute. The early blows are more effi- 
cient than the later, and longer drops also are more so 
than shallow ones. But the deeper the drop and the 
more prolonged the action, the more severe are the 
effects on the mechanism of the mould. Destructive 
effects can only be avoided by a very solid construction, 
and by the recognition of certain facts which are con- 



EXAMPLES OF MOULDING MACHINES 325 

cerned with the impact of faUing bodies. Fracture of the 
sand will also occur in any case if there is imperfect fit- 
ting of patterns, flasks, or mechanism, which would cause 
slight relative movements to take place. 

By the laws of impact the heavier the anvil the better, 
so that an ^nvil bedded on rock would be the ideal one. 
But a rock bottom would be bad from another point of 
view. It would transmit the ground waves set up by the 
machine to a long distance, with disagreeable if not 
destructive effects to neighbouring walls, floors, and 
buildings. And a very heavy cast iron anvil would in- 
crease the cost of the machine unduly. The practice 
therefore is to make the anvil of about the same weight 
as the jarring table when loaded with its pattern, flask, 
and sand, and to bed it on a timber cribbing. An anvil 
cushioned in this way will, when struck by a table of its 
own weight suddenly acquire one half the velocity of the 
table at the instant of impact, after which both table and 
anvil wdll be brought to rest by the yielding resistance of 
the timber foundation. The loaded table thus loses only 
one half the velocity it would lose by falling on an anvil 
of infinite w^eight, as a rock foundation, and the ramming 
effect is one quarter as much, being measured by the 
square of the change in velocity. 

Compressed air is used for the operation of these 
machines, its supply being controlled by a valve which 
is put into and out of action by a lever, but the action 
of which is continuous and automatic as long as the 
lever is retained in a certain position. There are two 
general methods of operation in use. In one the air 
which lifts the jarring table is exhausted into the atmo- 
sphere during the falling stroke. In the other it passes 
into the anvil cylinder and assists in raising the latter to 



32(; PF ACTIO AL IBON FOUNDINa 

meet the falling table, the rest of the work being atVocted 
by compressed springs under the anvil. When the air is 
not exhausted thus, the springs do all the work of lifting. 
The idea is to cause the momentum of the rising anvil 
to be approximately equal to that of the falling table at 
the instant of impact, and so produce a maximum of 
jarring effect on the sand without injurious shock on the 
foundations, on the sand, or the mould fittings. ]>y this 
action the tendency of the table to spring away from the 
anvil after impact is met and neutralized, since the 
rising anvil remains in contact with it, and one of the 
causes which would tend to produce damaged moulds is 
eliminated. 

Specialization in the foundrii. — We are coming into a 
time in which the work of the foundry is likely to un- 
dergo radical changes, not only with respect to the em- 
ployment of moulding machines, but of the system of 
which they form an important section — though but a 
section after all. For, though the installation of a 
machine or machines in a shop is, in the first place, 
usually done with the idea of helping the jobbing work, 
or that which is but slightly repetitive, dissatisfaction 
with all the methods in vogue usually results, as the 
latent possibilities of the innovation in moulding be- 
comes apparent. 

The introduction of any moulding machines, therefore, 
however simple in design, and few in numbers only, is 
often the beginning of a wider system, of which this 
particular machine forms but a single detail. Though 
the advantages which it confers over the unassisted work 
of the floor or bench are great, its ultimate tendency is 
to lead to economies in all the work that leads up to 
the machine, and in that which follows. The desire to 



EXAMPLES OF MOULDING MACHTNES 327 

specialize grows as the economies of one particular 
section of specialization becomes apparent. It tends to 
introduce, and must with some machines introduce, 
new types of moulding l^oxes, new methods of mixing 
and conveying sand, of grading iron, of making cores. 
The labour problem has to be wholly readjusted, while 
questions come up for solution that never trou])led old- 
time moulders — such as the installation of power (steam, 
hydraulic, or pneumatic) in the foundry. 

Perhaps the keynote in the problems which are raised 
is to be sought in the word " specialization." Firms who 
are able to specialize sufficiently, can choose almost any 
system and moulding plant, and make a success of it. 
Those who have grown accustomed to one system are 
naturally prejudiced in its favour, and it is hard for out- 
siders to say whether it is worse or Ijotter than any other 
for particular shops. Generally, one would like to believe 
that firms can be trusted to know their own business re- 
quirements better than any others can know them. Yet 
this is not always true, because outsiders in walking 
through shops see, almost as if by intuition, things which 
might be improved; though long habit in the case of 
those who have grown with the system has developed 
a kind of permanent set, or, to use another simile, a 
colour blindness, which is prejudicial to clear insight 
and reform. 

An instance of what we mean )jy extreme specializa- 
tion is this: 

In the machine-made moulds in the ordinary work of 
the foundry, the box parts are put together either by 
hand or by the crane, in both cases the controlling power 
being exercised by the hands of the men. There is not 
very much involved in this, it is true, but it does some- 



328 PRACTICAL IRON FOUNDING 

times happen that a cope will be damaged by not being 
lowered quite horizontally, or hitching of the pins in the 
holes occurs, or because the movement is jerky. And 
when intricate cores are being inserted, these may be- 
come pushed aside, or crushed in the act of closing the 
mould. Now a machine is made by which the top is 
lowered on the bottom box, perfectly plumb, and it 
thus fulfils the same function in the accurate closing 
of the mould that the moulding machine does in a 
square lift of the pattern. It stands on a circular base, 
carrying the table on which the bottom box is laid. Two 
uprights stand up from the table, and carry centring pins 
that pass from bottom to top. The top box being sup- 
ported by hydraulic pressure, the removal of the latter 
allows the box to descend, along with a supporting cross- 
piece moving in guides underneath the table. Or, worm 
gear is substituted for hydraulic power. The capacity 
of these machines ranges from boxes of 24, 36, and 
48 in. in length. These are limited by the distances be- 
tween the uprights, but there is no limit to any width, 
within reason. 



CHAPTER XV 

MACHINE MOULDED GEARS 

Gear wheel moulding machines, though extensively used, 
are not found in all shops, so that there are still many 
moulders and pattern makers who have had no experi- 
ence whatever of them. There are six or seven different 
types. The machine of Messrs. Buckley and Taylor, of 
Oldham, is selected for illustration in this volume. Before 
discussing the actual moulding of wheels, the construc- 
tion of the main framework of the machine may he 
descrihed. 

The illustrations. Figs. 223 and 224, represent a table 
machine, that is, one in which the moulding flasks are 
set and rammed on a tahle. In the floor machines the lower 
portion of the work is rammed in the foundry floor, and 
a top box is employed to form the cope mould only. 
The first machines are used for wheels of small and 
of moderate dimensions, the second for those of large 
diameter. The table machines are entirely self-contained, 
but all the upper portions of the floor machines are 
portable, that is, the essential dividing apparatus and 
carrier arms are, when required for use, set down over a 
central pillar or base sunk permanently and levelled in 
the foundry floor. The machine of Messrs. Buckley and 
Taylor is made capable of employment in each capacity, 
the upper portion being removable, and the base, with 
the dividing apparatus, being adapted to fit into a 

329 



330 



PRACTICAL IRON FOUNDING 



massive bed in the floor, while a radial arm, made to 
sbVle in vee'd guides screwed upon the lied, is substituted 




Fia. 223. — Wheel Mouldino Machine. 



for the arched arm. This radial arm carries at one end 
the vertical slides for the tooth block, and the radius of 
the wheel to be moulded is only limited by the length 



MACHINE MOULDED GEARS 



331 



of the arm. Wheels up to 25 ft. are moulded in the floor 
machine. 

Figs. 223, 224, are an elevation and plan respectively^ of 




PLAN 



Ftg. 224. — Wheel Moulding Machine, 

the machine. In these, H is a strong foundation 
against which the bed I is bolted. The table fits LI 
by means of a turned pin into the boss of the foundation 
plate IT. This table carries the moulding flask 1\ on 
which is shown a sectional portion of a spur wheel mould, 
and is revolved by means of the dividing wheel F, and 



332 PRACTICAL IRON FOUNDING 

tangent screw E. The bed / carries the arched arm J, 
at the extremity of which moves the vertical sUde K, to 
which the tooth block is bolted. 

The essential mechanism by which the dividing out of 
the wheel teeth is effected is as follows. The dividing 
wheel F is attached to the mider side of the table. Into 
this gears the tangent screw K. This is actuated by the 
handle A turning around on a notched division plate T". 
The short hollow pillar beneath encloses a pair of small 
mitre wheels, through which the motion of the handle A 
is communicated to the shaft 7>, at the opposite end of 
which the first change wheel C is placed. This gears 
through the idle wheel G with the change wheel C upon 
the tangent screw shaft IK Any gears of the set usually 
supplied with these machines are interchangeable at 
0, C and G, a slotted quadrant plate, together with the 
idle gear G furnishing the means of adjustment for 
centres. Of course the idle wheel counts for nothing in 
the calculation of the train. 

Suppose the tooth block to have been set at the correct 
radius for any given wheel to be moulded, by the sliding 
along and clamping of the arm J, on the bed /. It is 
evident that a single turn of the single threaded worm E 
will pass the dividing wheel F a distance equal to one 
tooth. Hence, having wheels of equal diameter at G and 
C\ and giving one turn to the handle A, a wheel would 
be moulded on the table having precisely the same 
number of teeth as the dividing wheel. But by employ- 
ing unequal change gears to connect the handle shaft 7>, 
and the worm shaft I), and by doubling or trebling or 
quadrupling the number of turns of the handle, or by 
giving to the handle some definite fractional portion of a 
turn only, we liave, as in tlie screw-cutting lathe, a means 



MACHINE MOULDED GEARS 333 

for establishing almost any number of proportional rela- 
tionships between the number of teeth in the dividing- 
wheel F and the wheel to be moulded. Hence the rule, 
'* As the number of teeth in the dividing wheel is to the 
number of teeth in the wheel required to be moulded, so 
is the number of teeth in the wheel on the handle shaft 
to the number of teeth in the wheel required on the worm 
shaft." 

Thus : suppose a wheel of 100 teeth has to be moulded. 
The dividing wheel F has usually 180 teeth. Put, say, a 
90 toothed wheel on the handle shaft. Then: — 180: 
100 : 90 : : 50. A wheel of 50 teeth would therefore be 
placed on the worm shaft 7>, and one turn given to the 
handle shaft B. But supposing we have not got a wheel 
of 50 teeth, we can multiply 50 by 2 = 100, and put a wheel 
of 100 teeth on the worm shaft. But then we must give 
two turns to the handle. For in any case, if we multiply 
the quotient which gives the number of teeth on a 
change wheel on the worm shaft, we must also multiply 
the number of turns of handle, or if we halve the number 
of teeth, we must halve the number of turns given to the 
handle. 

If we are doubtful of the wheels, they may be proved 
thus. Divide the number of teeth in the wheel on the 
handle shaft by the number of teeth in the wheel on the 
worm shaft, multiply the quotient by the number of 
turns given to the handle. The product will be equal to 
the quotient of the number of teeth in the dividing wheel 
divided by the number of teeth in the wheel to be 
moulded. Thus in our first example: — 



334 PRACTTCAL IRON FOUNDma 

ILindle shaft ... 90 

— =1-8x1 turn = 1-8 



Wonii shaft .... 50 

Dividing wheel . . . 180 

-1-8 

Wheel to 1)(! moulded 100 

The mechaniHm for actuating the tootli block is as fol- 
lows: — ^The tikHiis of the block is adjusted by means of 
the arched arm J, which travels upon the bed /, to or 
from the centre of the table. This is adjusted with the 
screw L, and clamped by the pinching screws in its foot 
in its required i)osition, remaining immovable during the 
whole period of the ramming of the wheel teeth. The 
vertical slide K is carried in vee'd guides, which have 
])rovision for taking up wear. It is actuated by the 
small hand wheel O turning the worm P, which re- 
volves the worm wheel (J, upon the spindle of which is 
the s[)ur pinion U, gearing with the rack S attached to 
the vertical slide K. The slide is counterbalanced by the 
weight M. The vertical movement of the slide is checked 
at the proper position by means of the adjustable stop U, 
so that there is no risk of the tooth block being thrust 
down too hard upon the sand bed. The lower portion of 
the slide receives the carrier N to which the tooth ))lock 
is attached. 

Tlie essentiiil portions of the machine are therefore 
the lirni base //, the; revolving table cariying the ilask, 
7', with the dividing apparatus, the arm J moving radially 
in reference to the table, and the provisions for the 
vertical movement of the tooth block. The tables IT, A', 
are simply convenient attachments for the reception of the 
moulder's small tools. We are now in a position to take 
u[) the details of the actual moulding of toothed wheels. 



MACHINE MOULDED GEARS 



335 



Sjxir (/ears. — These are moulded very simply. The 
teeth are formed with a block, and the arms by means of 
cores. The block, Fig. 225, in this case, has two teeth 
only, and the inter-tooth space alone 
is used in the formation of the mould. 
Three teeth. Fig. 22(3, or four are often 
used on the block. A bed is first struck, 
Fig. 227, with a board attached to the 
striking bar ^, the depth B being equal 
to the depth of the face of the wheel, Fig. 225. — Tooth 
the bottom edge C striking the bed, Block. 

the top edge ]J the top or joint face. 
The striking bar A in Fig. 227 is turned to lit into the 
bored hole in the centre boss of the table in Figs. 228, 







Fig. 226.— Tooth Block. 




Fig. 227. — Striking Board. 



224. The slraj) E is bored to lit over this bar, and 
its shoulder F is cut to a definite distance from the 
centre of the bar, so that the radius of any striking board 
is less than the radius of the wheel by the distance G. 



336 PRACTICAL IRON FOUNDING 

The central bar or post A is removable at pleasure. Its 
purpose is, first, the carrying of the strap or bracket E, 
and second, it is the part from which the radius of the 
tooth block is measured. 

The vents from the bed are carried down to a coke 
bed if the wheel is moulded in the floor, to the bottom of 
a flask, if in a flask. The tooth block is screwed to the 
carrier, set to the correct radius, either by means of a 
strip or gauge cut to reach the precise distance from the 
post of the machine to some portion of the block, — 
either root or point, and the machine is clamped to pre- 
serve that distance constant. The length of the gauge 
will be ecjual to the radius of the root or point, as the 



Fig. 228. — Eadius Gauge. 

case may be, minus the radius of the post. Or a gauge, 
Fig. 228, may be cut to lit partly round the post A in 
Fig. 227, and the radius be marked upon that to root or 
point. The radius once obtained, and the arm clamped, 
the gauge strip is no longer required. The block is 
lowered until its lower face bears upon the sand bed, and 
then the stop U, Fig. 224, is clamped, and all is in readi- 
ness for the ramming of the teeth. 

It will be noticed that the end 11 of the board in 
Fig. 227 is bevelled. This is not always done, but it is 
a good plan, as is apparent by the sectional view in 
Fig. 229, where the tooth block is seen in its exact 
relationship to the circular wall of sand A, within which 
it is rammed up. Space is left between the points of the 
teeth, and the outer roughly-struck wall of sand, in order 



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MACHINE MOULDED GEARS 



337 



to give a narrow zone for ramming facing and strong 
sands into, and the wall is made sloping, because it is 
easier to sweep up than a perpendicular wall, from which 
the sand would tumble down. 

Facing sand is thrown into the space between the wall 
A and the teeth, and strengthened with nails (dotted). 
The sand is rammed between the teeth with a small 
pegging rammer, being, for these small teeth, only 
a rod of round iron flattened and narrowed at one end. 
When the inter-tooth space is filled, the sand is levelled 
over with a flat rammer, scraped and sleeked with the 
trowel, and vented diagonally, the 
vents B passing into a main vent 
C, either going down to a coke 
bed, or coming out in the joint of 
the flask. Only the inter-tooth 
space gives the tooth shape, and 
one tooth space or more may be 
rammed at a time (see Figs. 225, 
226). The hinder part and the 
ends of the block are slightly 

rapped with the hammer previous to the withdrawal of 
the teeth; but there is no rapping in the sense in which 
it is employed with ordinary patterns. The pattern is 
simply started, and the block lifted without any sensible 
lateral play. There is, or should be, no taper in the tooth 
space, and the sand would therefore become torn up on the 
withdrawal of the block but for the fact that it is held 
down by a stripper bit cut to the shape of the inter-tooth 
space, upon which the moulder presses the two forefingers 
of his left hand, while elevating the slide with his right. 

Having lifted the block clear of the mould, the re- 
quisite number of turns is given to the handle shaft, and 




Fig. 229. — Eamming 
OF Tooth Block. 



338 



PRACTICAL IRON FOUNDING 



the block thereby carried round a distance equal to the 
pitch. The slide is then lowered, bringing the block into 
a suitable position for ramming the succeeding tooth or 
teeth, the process for each tooth being simply a repetition 
of the first. In order that the outside faces of the teeth 
on being lowered shall not scrape or push aside the sand 
already rammed, taper is given to those faces, as shown 
in Fig. 226, so that the outer edges of the block do not 
come into actual contact with the sand at all, or at least, 
only when finally in place, the top edge may just coincide. 
Also, to prevent the sand from tumbling down on the side 







r 



Fig. 230. 

Section of Wheel Marked 
ON Board. 



Fig. 231. 

Section through 
Mould. 



opposite to that which is already rammed, a block of 
wood is laid against the tooth block to sustain the sand 
in that direction during ramming. 

Striking boards also are desirable, though not always 
necessary in the case of perfectly plain wheels. But it is 
better to use them even for these. A plain wheel can be 
made by ramming the teeth round on a level bed, insert- 
ing the arm cores, and covering with a plain top. But if 
a board like Fig. 227 is used, it forms a wall of sand 
within which the facing sand used for surrounding the 
wheel teeth is rammed, and it gives the exact depth also 



MACHINE MOULDED GEARS 



339 



of the wheel, and the face upon which the top is to be 
laid. Such a board is made parallel, so that a spirit level 
is tried upon the top edge, without which precaution the 
board may become tilted a little, and strike a bed that is 
slightly dished. The edges are chamfered like those of a 
loam board. A careful man will mark the section of 
wheel rim and boss upon the board, Fig. 230, and cross 
hatch it as a guide to the moulder. Sometimes a narrow 
strip is tacked on the board at the exact radius of the 
points of the wheel teeth, instead of indicating the teeth 





Fig. 232. Fig. 233. 

Boards for Striking Half Shroudings. 



with crossing lines, as in Fig. 230. Fig. 231 shows the 
mould in section. 

Half shroudings furnish the commonest cases in which 
the use of a plain top is not possible. Made in the man- 
ner first mentioned, by ramming the top on a reverse 
mould, Fig. 232 shows the striking board used, the edge 
A being for the bottom and the edge B for the top, both 
edges also including the bosses, the position of the board 
being of course reversed for the separate operations. 
Usually one piece of board serves thus for both the 
opposite edges, being cut to the shapes required; but 
sometimes separate boards are made. The edge B is 



340 



PRACTICAL IRON FOUNDING 



used first, striking a reverse top on which the actual top 
mould is rammed. Afterwards the sand is dug out and 
the edge A is used, striking the wheel face to the proper 
depth below the top face. The advantage of this method 
is that the top and bottom are bound to be concentric, 
the former having been rammed in the actual place 
which it will again occupy after the ramming of the teeth 
and the coring up are done. In the other method the 
edge which strikes the top is like that one which strikes 
the bottom, and the fitting of the boxes ensures the top 




Fig. 234. — Board 
FOR Plated Wheel. 



Fig. 235. — Wheels Cast 
Together. 



and bottom being concentric. Or a check is used, as in 
loam work. 

Fig. 233 shows a board used for striking a top mould 
directly, the shape of the half-shrouded wheel being 
marked upon it. The correspondencies are clear. The 
interior is formed with cores, for which prints are pro- 
vided. Fig. 234 is a board for a plated wheel in which 
the recessing is swept in the mould. Generally, when a 
wheel is plated, the plate and interior of the rim are 
formed by annular cores made in an annular box. 

When wheels have to be cast together, as in Fig. 235, 
or in other combinations, they can be bedded in the floor, 
making suitable joints for shroudings, and moulding the 
pinion first. Or they can be prepared in two separate 
boxes, which will have to be centred properly. 



I 



MACHINE 3I0ULDED GEARS 



341 



When facings are cast on the rim, or on the arms of 
wheels moulded from tooth blocks, they are set in place 
singly by measurement — work that can be done by centre 



^^oj-V Ul/i 



L^ 




Fig. 236. — Large Boke formed with Segmental Cores. 

and circular lines set out on the plain bed. The pattern- 
maker is usually called upon to do this. When such 
pieces come in the top, there is an advantage in laying 




Fig. 237. — Large Bore and Arms formed with 
Segmental Cores. 



them on a reverse mould and ramming the top over 
them. 

The tooth block moulds a ring of teeth only, and the 
interiors of the wheels have to be formed with cores. 



342 



PRACTICAL IRON FOUNDING 



These are made from boxes, and are covered with a top, 
plam or otherwise, with boss facings bedded in top and 
bottom. Usually the H- section arm is employed for 
wheels made by machine, because it is easier of forma- 
tion in cores than any other shape; but any shape can 





Fig. 238. — Arm Core. Fig. 239. — Section of Cure. 

be made if required. In patterns the J_ ^ype of arm is 
easiest to make. 

Arms. — The cores for anus are made in dried sand, 
and set in place without prints, by measurement alone. 






Fig. 240.— Grid 
FOR Arm Core. 



Fig. 241. 
Abutting Cores. 



Fig. 242. 
Dished Arm. 



The arms of spur wheels are usually H shaped in sec- 
tion, partly because of their superior strength, but chiefly, 
as stated, because they are rather easier to make than 
arms of + section or _L section. If a ring of teeth only is 
required the interior is formed with segmental cores, as 
in Fig. 230. Or if the bore is large and the arms short, 
with two sets of cores as in Fig. 237. 



MACHINE MOULDED GEARS 



343 



A core for H section arms is seen in plan, Fig. 238, a 
section in Fig. 239, and its grid in Fig. 240, and the core 
also in Fig. 231. The core is rammed upon the grid, the 
central part heing composed of cinders, the main vent 



D- 




T(llTH,i ■■? •-/;'•■' ''^"tl-' ' ■ • '^k'^."- ■':■■•• ■ 

:^::?.:.v;:•••^.•.••^v■•^;••.^ .^'t^. 



Fig. 243. — Board for Reverse Mould. 

being brought off at the top, A, into which all the 
smaller diagonal vents are carried, as well as the vents 
from the cinders. 

Wheels having arms of + or _L shape can be also 




Fig. 244. — Board for Striking Bed. 

made in cores, but the difficultj^ is that these cores have 
to abut and joint against each other, while with the H 
form they are kept asunder by an amount equal to the 
thickness of the vertical arm. The joints must abut when 
the edges of the arm are convex, Fig. 241; also, wdiile the 



344 



PRACTICAL IKON FOUNDING 



top and bottom faces of the cores for H arms always 
lie in the same plane as the faces of the wheel teeth, 
those of the other sections usually do not. A special 
bed and cope then have to be struck, and cores shaped 
to correspond, Fig. 242. 

Bevel gears. — Fig. 243 shows the method of making a 
reverse mould for a bevel wheel, where A is the board, 
swept round over a hard-rammed bed of sand, B. The 
edge C coincides wdth the top edges of the arms, and 
therefore with the top face of the cores of the bevel 
wheel, and D is the joint face dividing the cope from 




Fig. 245. — Board for Striking Cope Direct. 



the drag. Upon this bed, the board being removed, the 
top or cope is rammed, parting sand intervening — being 
littered and vented precisely as though it were being 
rammed upon a pattern. This is then taken away, and 
after the wheel is moulded and cored up, is returned 
finally into position. 

On the removal of the cope, the sand which formed 
the reverse mould is dug out, and the board for striking 
the lower face, and corres^^onding with the tooth points, 
is attached to the strap and slipped over the bar. Fig. 
244, the edge, A, coinciding with the joint face, D, 
already struck by the previous board, and the bottom 
sand swept out. The tooth block is then attached 



MACHINE MOULD ED GEARS 



345 



to the carrier and set in position, and the ramming, 
naib'ng, and venting proceed generally on the same 
methods as those pursued in the case of spur wheels, 
modified only by the bevel form. The alternative 
method of making the cope by a direct process is as 
follows: The centre pillar always has a movable collar 
fitting over it, seen in Fig. 244; this collar is set and 
pinched in such a position that its top face coincides 
exactly with the top or joint edge of the tlask on the 
table, as checked with a straight edge. The boards, both 
for striking the cope and the drag, have strips nailed 




T_"_ia 



Fig. 246. — Board foe, Striking Bed. 



upon them, sometimes one strip only, sometimes two, 
the distance between the strips in the latter case being 
equal to the width of the strap, and the inner face of 
one strip coinciding with the joint edge of the mould. 
Figs. 245, 246, show the two boards, Fig. 245 striking the 
cope direct. It is clear that the collar remaining in the 
same position on the post, the joint faces, A, A, of cope 
and drag will coincide, if the fittings of the flasks and 
post are perfect. In work of this kind the flasks have 
properly to be turned and checked on their joint faces, 
specially for wheel moulding, but in the method first 
described any flasks can be used, and the wheel can be 
moulded in the floor just as well as on a table. When 



;ji(; PJUCTKJAL lUON l^'OUNDlNd 

wIicoIb tiro moulded in llio Hour llio liisi luoiliod is iliu 
only one which can ho ado])ic3d withoui risk of a crush 
or of Jiiiiiiii<^ occurrin«^. 'IMio copo hoinj^ rammed in 
place must, when ih(! uiould is clos(!d foi* cMsting, make 
a perfect joint witli the mould in tlu; lloor. 



CllAPTEK XVI 

MISCELLANEOUS ECONOMIES — WEIGHTS OF CASTINGS 

One of the duties of foremen lies in scheming other ways 
of working than those which are reguhir and common- 
place. Occasions arise when, for economical reasons, it 
is desirable to get away from these and adopt other 
methods. 

The question of numbers of castings required all alike, 
or nearly alike, generally determines in the main the 
methods of the pattern-maker. But dimensions also, 
whether large, small, or medium, have to be considered 
as well. So also have shapes, whether irregular or 
regular; as circular, which is admirably suited for 
sweeping up; or rectangular, for skeleton or sectional 
framings; or irregular, which cannot be so well treated. 
These things explain why the ideas of difi'erent men vary 
so much as to the most suitable methods of moulding, 
and of the amount of assistance which should be given 
to the moulder by the pattern shop, having regard to 
the relative expenses of each department. Broad views 
and due balancing of costs are therefore requisite in the 
conduct of these departments, which should never be 
regarded as having isolated interests. 

As there are several alternative methods of working 
to achieve the same results in the ultimate forms of cast- 
ings, we will consider the broad divisions of work just 
now instanced, those of numbers off, along with those of 

347 



848 PRACTICAL IRON FOUNDING 

dimensions and of shapes, since neither stands in a 
state of isolation from the others. 

The usual method when numbers are required all alike 
is to mould from complete patterns, made exactly like 
their castings, save for core prints and cored portions. 
And as the numbers off increase, more care is bestowed 
upon pattern construction, either in regard to the char- 
acter of the wood w-ork, or in the abandonment of wood 
for metal, and also by pressing into service the aids to 
be derived from mechanical methods of moulding. 

In the pattern shop the difference lies in whatever is 
included in the terms rough patterns, and standard ixit- 
terns. This means a great deal in extreme cases. A 
rough pattern may be broken up immediately that it is 
done with ; and when that is the case, not a penny more 
is spent on it than is absolutely necessary. More work, 
of course, is thrown on the moulder, who will have to 
rub his fillets and the print portions of the cores, and 
will often have to work wdth sweeping boards or skeleton 
coreboxes, or with no boxes at all. Some parts will be 
made fast, instead of being dowelled, and the work will go 
into the foundry unvarnished, and without rapping or 
lifting plates. 

On the other hand, a standard pattern in its best form 
will be perfect in dimensions and in finish. All fillets 
and radii will be put in, cores will fit their prints with- 
out rubbing, every core will be made in its own box 
ready for use, loose pieces will be fitted where there is 
the slightest risk of the mould breaking down if they 
were fast; and they will be so fitted, and the cores also, 
that it will be quite impossible for a careless moulder to 
set them in any but their correct positions. There will 
will be no excuse for a moulder to drive his bar or spike 



MISCELLANEOUS ECONOMIES 349 

into such a pattern for rapping and lifting, for plates or 
straps will be provided where required. Care will be 
exercised in the selection of timber, which will be pro- 
tected with three or four coats of varnish or paint, well 
rubbed down. 

Between these extreme cases most patterns are made. 
Besides these, metal patterns are substituted generally 
for wood in small standardized articles, and in machine- 
moulded work. 

But as there are many classes of jobs which are never 
repeated in large numbers, here the debatable ground 
lies. These include all engine cylinders of large dimen- 
sions, large fly-wheels, unusual sizes and shapes of 
columns, pipes, and bends, large drums for winding and 
hauling, big pulleys and sheave wheels and toothed 
gears, either of which may be made in one of two or 
three methods — namely, from full patterns, or in com- 
bination methods by the aid of sweeps in green sand or 
loam by the aid of fractional pattern parts, or of moulds 
in conjunction with such portions or sections of patterns 
and coreboxes that do not lend themselves to methods 
of sweeping uj). The mere mention of these items will 
call up to the mind of a founder numerous alternatives 
possible in the production of a mould. 

Dimensions, we said, determine methods of working 
to a large extent. Thus, methods which are practicable 
with castings measuring from a few inches to 3 ft. or 4 ft. 
across are often unsuitable for those of larger sizes, 
either for economical or other reasons. But in con- 
junction wdth dimensions, shapes also exercise much 
controlling influence in the choice of methods. Any 
symmetrical particle, no matter how large, suggests at 
once the employment of sweeping up, for which either 



850 



PRACTICAL IRON FOUNDING 



green sand, or dry sand, or loam, are often equally well 
adapted. And if an object is not wholly adaptable to 
this method— as, in fact, few are— then it is always 
practicable to utilize pattern parts or cores to complete 




Fig. 247. — Skeleton Frame. 

the work, whether done in green sand, loam moulds, or 
loam patterns. 

Alternative methods. — The alternative methods, there- 
fore, of the foundry may be very broadly classified thus : 
Complete patterns made in the ordinary way for hand 
moulding. Complete patterns in which mechanical aids 









-^^rr^ 



Fig. 248. — Strickle, 



are utilized. Work which is moulded without complete 
patterns, which includes skeleton patterns and moulds 
taken from broken castings, as well as swept work. Also 
a large class of moulding made from segmental patterns, 
and sectional patterns in which a combination of several 
methods is utilized, such as pattern parts, sweeps, and 



MISCELLANEOUS ECONOMIES 



351 



coreboxes together. Lastly, there are devices for making 
moulds differing in some respects from their patterns, 
which includes alterations of certain details only; as of 
patterns in some degree standard, to which supple- 




r^rr-^-^- -, 



~^:£^=HEE:i:=-^F^_-^1S^ 



^^M 



Fig. 249. — Strickle and Frame. 

mentary parts may be fitted, or in the. moulds, in which 
stopping-off is done; or both devices may be effected in 
the same mould in conjunction. 




Fig. 250. — Strickling a Curved Plate. 

In any of the methods of moulding, in which a com- 
plete pattern is dispensed with, there is a larger element 
of risk present, that of inaccuracy, than there is when a 
full pattern is employed. This arises in all work that is 
either swept up, or marked out on sand beds, or where 



352 



PRACTICAL IRON FOUNDING 



pattern parts are bedded in green sand or in loam, or 
attached to loam patterns. These risks the pattern- 
maker is expected to foresee and guard against, and to 
accept responsibility for, even though the carrying 
throu2:h of the work lies in the moulder's hands. As a 




Fig. 251. — Edges of a Corebox cut for Strickling. 

general rule the pattern-maker has to spend some time 
in the foundry, more or less, during the progress of such 
jobs, either marking out centre lines, or measuring-in 
parts, or checking the mould at certain crucial stages. 




Fig. 252. — Edges of Box cut for Strickling. 



Skeleton Frames. — Take a large plated casting, with 
or without flanges, say for a floorplate, a backplate, a 
tankplate, or a buckleplate, to be moulded from direct, 
or for making a metal pattern from for moulding in 
quantity. Instead of battening up narrow boards to 
make a continuous large area of, say, 4 ft. to G ft. 
square, a frame only is made, Fig. 247, of narrow strips 



MISCELLANEOUS ECONOMIES 



353 



5 in. or 6 in. wide, the outside dimensions and the thick- 
ness only corresponding with those of the casting. 

The interior of such a frame cannot be rammed on, as 
a solid-plated pattern can. So it is filled with hard-rammed 
sand, strickled off level with the top face, and the top box 



TT 



■^er 



Fig. 253.- -Strickling a Sand Bed for Pattern 

OR Core, 

is then rammed on that. But if such a frame is used for 
an open sand mould, as many foundry plates are made, 
it is not filled up. A strickle like Fig. 248, having the 
depth A of its notch equal to the thickness of the plate, 
strickles out the sand level and true with the bottom face 




Fig, 254. — Levelling a Bed. 

of the plate. Fig. 249. On the delivery of the frame the 
mould remains just as though a solid-plated pattern had 
been used. 

And if the plate should be crn-ved (Fig. 250), as, say, for 
lighthouse, or tubbing plates, the frame can be made as 
shown, and the strickle curved to correspond. Or a 

A A 



854 



Pit ACTIO AL IRON FOUNDINO 



Htrai^lit Htricklc! can Ix; UHcd, Hwceping in the other 
direction. The illustration is given to show that a strickle 
is Bometim(!K curved; it is sometimes also of an irregular 
shape, as straight and curved in combination. 






Fig. 255. — Thicknessing Facing Sand. 

Strickles are used thus in corebox work as well as in 
stopi)ing down moulds or i)ortions of the same. The 
curved face of a core can he obtained by strickling round 







/ J. 



Fkj. 250. — SwKKi'iNu A Levkl Bed. 



the edges A, A of the box in l^'ig. 251, just as well as by 
cutting a concave block of wood expensively, and fitting 
it in the box. So can the edge of tlio box in Fig. 252, 
while a bed foi' tlie pattcirn and core can be strickletl as 
in Fig.^258. 



MT80ELLANE0UH ECONOMIES 



Levellinr/ Beds. — Level beds are in constant request, 
either for laying flat patterns or portions of patterns on, 
the edges of which are then rammed around, also for 
bedded-in work, or in some cases for ramming plain 
tops on, or tops on which otherwise plain facings, lugs, 
brackets, or prints have to be measured on and set to 




Fig. 257.— The Use of 
Segmental Gores. 



-TfFa 







Fig. 258. — Box for Seg- 
mental Cores. 



be rammed over. Such plain level beds are variously 
made. 

A frequent method is to lay two parallel strips or 
straightedges in the sand, bedding them down with the 
mallet, and testing with spirit level along and across, 
and with parallel strips, Fig. 254. Then the top edges of 
the strips embedded in the sand become guides for a 
straightedge or a plain strickle by which the sand is 
levelled. At the same time venting and ramming will 



356 



PRACTICAL IRON FOUNDING 



be done to form a firm, suitable bed for moulding on. 
The black floor sand is treated first, being rammed, 
vented, and strickled level with the tops of the strips, 
and then, if required for a mould, a layer of facing sand 
of about an inch in depth is rammed on this thick- 
ness, pieces being put on the straightedges as guides, 
Fig. 255. If the bed is only for ramming a top on, the 
facing sand is not wanted. 




Fio. 259. — Loam on Coke Plates with Lugs, 



Another way to make a bed is to utilize the centre 
which is employed for striking bars, and bolt a plain 
strickle to it, taking care to level it properly, Fig. 256. 
Foundry appliances are made thus with little or no 
assistance from the pattern-maker by the aid of strickles, 
straightedges, sweeps, and plain thickness pieces. Thus, 
a circular loam or core plate can be swept up as in 
Fig. 256, with a board notched, as shown at A, fastened 
to tho striking bar. An alternative method is to strike 



MTSCELLANFOUS ECONOMTTJS 



357 



a plain bed by the method of Fig. 254, and form the 
edge by means of segmental cores, Fig. 257, made from 
a box like Fig. 258. If lugs are wanted for lifting slings, 
Fig. 259, they are cut out of the cores, or blocks of wood 
are bedded in if the plate is swept up by the board in 
Fig. 256, A. 

When smaller plates are wanted, as for core plates, 
Fig. 260, the moulder borrows a flange from the pattern 
stores and beds it in in open sand, cuts off some round 




Fia. 260.— Core Plate. 



Fig. 261. — Ramming Edges 
AGAINST A Strip. 



cores, and weights them down, and so makes his mould. 
If many plates are wanted, he has a few iron patterns 
of various sizes made and hung up in the foundry for 
stock service. 

Kectangular frames for foundry use, as for back plates 
of boxes, core plates, etc., are made without even the 
wood framing of Fig. 247, by levelling a bed by the 
method of Fig. 254, and then marking out the size and 
shape of the frame, and ramming the edges against a 
strip of wood. Fig. 261, of the same thickness that the 



358 PRACTICAL IRON FOUNDING 

plate has to be. The edge of a circular plate can be 
rammed with a piece having a curved edge, Fig. 262. 

Plates for loam work, and core plates like Fig. 260, 
are gaggered over without aid from the pattern-maker by 
sticking some stout nails into a handle. Fig. 263, and 
pushing these into the sand all over the surface required. 

Sireepinfi in Greensand. — In the simple strickle or 
sweeping board the moulder has the most valuable 
economical aid. There are, however, limitations to the 
use of striking boards in greensand work. It is im- 
possible to strike up vertical faces, whether deep or 
shallow, in greensand, though this can be done in loam. 




J 

";n 

TTTTTTT 
Fig. 262. — Curved Strip. Fig. 263. — Gagger Pattern. 

A vertical face of any depth can be swept truly in loam, 
provided the rough coat is allowed to set before the 
finishing coat is laid on, and the latter is kept thin. 
But greensand is too loose to hold together, and it will 
fall down from a perpendicular face; and this must be 
borne in mind when scheming methods. It limits such 
work to surfaces that are horizontal, or of moderate 
slope or curvature, beyond which ramming blocks must 
be used in conjunction with the striking boards. And 
the alternative of loam must not be rashly resorted to in 
all cases, because loam is more costly than greensand, 
due to the detailed labour of bricking, and to the cost of 
drying. 



MISCELLANEOUS ECONOMIES 



359 



Another useful function often fulfilled by sweeping 
boards is the preparation of faces, either to lay patterns 
on, or to ram top parts on. If we have a flimsy pattern 
to mould by bedding-in, it will be next to impossible 
to ram up such a pattern truly b}^ beating it down and 
tucking the sand under. The general level must be sw^ept 



Fig. 264. — Condenser Cover. 

up and the pattern laid on this, and any projections 
or recesses be then attended to in detail. 

The device of sweeping up a bed on which to ram a 
top has two advantages, besides the saving of cost in 
patternwork. One is that the top is bound to go back 
into exactly the same position relatively to the bottom 




Fig. 265. — Sweeping the Mould. 



for pouring. Another is, that small pattern parts, as 
facings, lugs, bosses, etc., can be measured in position 
exactly on the swept-up dummy mould better than they 
can be measured into the actual top. We will take 
examples illustrating the preceding remarks. 

The condenser cover, Fig. 264, is swept in greensand, 
Fig. 265, in preference to making a large solid pattern. 
If the outside of the condenser were turned bright, it 



360 PRACTICAL IRON FOUNDING 

would be made the opposite way down from that shown 
in the drawings. 

Two boards are necessary, one, A for the outer, the 
other, B for the inner face, both being attached to turn 
on any convenient centre C, such as that used for loam 
work, or for wheel moulding. The board A for the top 
is used first, and having formed a dummy mould 1) 
with it, the top ])0x is rammed upon this. 

The question may be asked, Why not strike the top part 
direct with a board shaped like a loam board — that is, 
cut the opposite way to ^? The answer is that when 
greensand is being rammed it is easier to ram it wholly 
without combination and interference with the work of 
sweeping up. Another good reason is that the top being 
rammedf inj place, goes back exactly right, guided by 
the stakes by which it is set on the lower mould in the 
floor, or by the pins in a box. 

After the top has been rammed and removed, the 
bottom E is swept out with its board B. The shoulder 
I\ though shallow, will have to be made good with a 
sweep. 

The moulding of fly-wheels with wrought-iron arms, 
in the absence of a full pattern, requires two boards and 
a sweep. The latter is of the same section as the rim 
of the casting, besides which it carries arm bosses and 
boss prints (see p. 170). 

Moulds modified from Patterns. — In nearly all shops a 
good deal_of makeshift work is done. It includes altera- 
tions in the depth of teeth of gear wheels, in rims, in 
thicknesses, in hubs, in the casting of wheels of dif- 
ferent kinds and dimensions together, and many other 
matters. Some alterations can be effected in the foundry 
without alterations in the pattern. 



MISCELLANEOUS ECONOMIES 



361 



Clianr/infi Depth of Patterns. — Suppose it often happens 
that a gear wheel has to be cast either shallower or deeper 
than the pattern wheel. In thejfirst case it will be stopped 
off', in the second, drawn. The pattern, therefore, would 
not be cut in the first place, nor increased in thickness 
in the second. But drawing and stopping off affect 
other parts besides the teeth. Obviously, if a pattern 
is drawn in the sand, the depth or thickness of arms, 
ribs, and l)oss will be increased by as much as the teeth. 
If it is stopped off, the depth or thickness of these will 
be reduced by as much as the teeth. This in some 




Fig. 266. — Stopping off a Wheel. 



cases involves a good^deal of work to be done all over 
the mould — so much, in fact, that if several castings 
altered thus were wanted, it would generally be cheaper 
to make a new pattern, or to have the wheels moulded 
by machine. We will take the two methods, and show 
in detail what has to be done in each case. 

Stopping Off. — Take a wheel of the commonest type 
moulded from a complete pattern, one with arms of 
T- section. Say the wheel is 3 in. deep and it has to be 
stopped off to 2i in. The first thing is to make a small 
strickle, Fig. 266, A, and in perspective in Fig. 267, 
which after the wheel has been rammed up will, on being 
worked round from its upper face all around the teeth, 
form a new joint face | in. below that made by the 



362 



PRACTICAL IRON FOUNDING 



pattern. So far so good: but then it follows that the 
arm mould is still f in. higher than the new joint face. 
Either the arms must, therefore, be cut out entirely, 
and a new pattern arm moulded by bedding-in, or the in- 
terior must be wholly formed anew 
by means of cores; or alternatively 
the wheel must not be strickled on 
the top face, but on the bottom, 
before it is turned over, and the 
vertical arms must be stopped off. 

This last is always the better plan 
to adopt in the case of a wheel of 
the type shown. Fig. 268, therefore, 
shows the stage of moulding at which the strickle is used — 
that is, after the ramming up of the wheel in the bottom 
box, previous to turning the latter over to take the 
cope. It necessitates, however, a three-part flask, because 
now there will be two joints at a and at h respectively, 




Fig. 267.— Using a 
Strickle. 




Fig. 268. — Stopping off a Wheel. 



instead of one at h only, as in the ordinary way of moulding 
such a pattern. The sloping joint at a is now strewn with 
parting sand, and the second portion of the box, a bottom 
part, is put on and rammed over it. Then the mould is 
turned over, the cope put on the joint face b, and rammed, 
and removed (it has been only temporarily rammed in 
Fig. 268); the pattern drawn, and the boxes parted at a. 



MISCELLANEOUS ECONOMIES 



363 



Fig. 269 shows the bottom part of the mould as it appears 
at this stage. Now all the tooth spaces c, which of course 
are f in. deep, are filled up with sand level with the 
joint face. Also the supplementary portions of the ribs 
are filled up with sand to the dotted lines and made 




.tf-'y^y.' v:..,\\r ^i _c 



tr' 



-ir 



i.3 E3 1^3 ESa ly;^ t ^^ t^TI R^^ !???!». 



|lUJ^ 



Fig. 269. — Stopping off a Wheel. 




good with a pattern rib. The hub also is filled up with 
a pattern boss. This completes the stopping off, which 
is done neatly and with comparatively little trouble. 

Pattern of Plated Type. — If the pattern is a disk or 
plated type of wheel, Fig. 270, then it is unnecessary to 
interfere with the disk at all. But 
the disk will be out of centre in the 
shallower wheel. In the event of 
this being considered objectionable, 
it is practicable to strickle down a 
new joint from each tooth face, the 
depth of each being equal to half 
the total reduction required. Then 
in the bottom the supplementary 
portions of the teeth would be filled up with sand in the 
way just noted, and on the top the cope would be 
lowered on the new joint formed directly by the strickle. 

Drawing. — Coming next to the work of drawing a 
wheel, and making use of the same examples as before, 
the ramming is done in the usual way. The wheel is then 
rapped and withdrawn. The distance to which it is with- 



FiG. 270. — Stopping 

OFF A Plated 

Wheel. 



364 PRACTICAL IRON FOUNDING 

drawn at this stage is equal only to the increased depth 
required. The exact depth is best gauged by means of three 
or four thickness strips ^, Fig. 271, laid on the joint face 
of the mould close to the pattern. The ramming is now 
continued up to the top face a of the wheel. At this stage 
the cope is put on and rammed, and lifted off. Then the 
pattern is withdrawn wholly from the mould, leaving the 
teeth deeper than the pattern. It often happens that 
some slight fracture of the sand will occur in doing this 
work, and then three mending-up teeth are made and 
used of the total depth of the drawn teeth. 

Ohjectionahle Results. — The flat arms obviously become 

^LaiiiiiiiiPi Piiiiiiiiiituun-uuuj-u 1 1 1 1 1 1 1 uiiniii iiiiTTim nmiiiiiMipFi-- " 



Fig. 271. — Drawing a Wheel. 

increased in depth by this operation, and a single stop- 
ping-off arm, Fig. 272, is made and used to reduce the 
moulded arms to the right thickness. The surfaces of the 
mould are hatched over with the trowel, and the pattern 
arm being put in place, sand is tucked underneath and 
made up good to the under- face of the pattern arm. The 
hub is similarly treated. All this is troublesome and 
tedious, and makes much mess in the mould, especially 
at the junctions of the separate arms with the boss and 
with the rim. 

In the case of a plated wheel drawn, the surface of 
the moulded plate is made good with sand to its proper 
thickness. 

Broken Castinf/s. — These are frequently utilized for 
moulding from, instead of making expensive patterns. 



MISCELLANEOUS ECONOMIES 



565 



Customers sometimes expect a moulder to do marvels 
with a broken casting. They sublimely ignore such 
matters as delivery, roughness of surface, recessed por- 
tions, holes, shrinkages, and the rest. All they can say 
is that they want a new casting without going to the 
expense of a pattern, and the moulder is expected to 
furnish it. 

Almost any casting can be moulded from, just as 
almost any pattern can be; but the question always 
arises whether it pays, having regard to the amount of 
work required to make it 
mouldable, and to the extra 
time occupied in the mould- 
ing. These, together with 
the numbers required, de- 
termine the alternative of 
moulding from old castings, 
or of making new patterns. 
The question is a very wide 
one, especially in jobbing 
shops, and it can only be 
settled after a considera- 
tion of the pros and cons in every individual case. These 
include the nature of the surfaces, the presence of 
broken parts, shapes suitable or otherwise for delivery, 
including coring, how to joint, shrinkages, the amount 
of wear which a casting has sustained, facility for getting 
it out of the sand, and allowances for tooling. 

The first thing to do with a casting to be moulded 
from, is to clean it thoroughly, which is generally done 
by making it red hot in a clean coke fire in order to burn 
off all grease, oil, and dirt. When cold it is brushed with 
card wire or rubbed with emery cloth, and is then taken 




Fig. 272. — Arm for 
Stopping off. 



366 



PRACTICAL IRON FOUNDING 



in hand by the patternmaker to prepare it for moulding. 
We will note the points to be attended to in various 
castings by some selected examples. 

Fig. 273 shows a double bracket fractured at K. This 
can be moulded from very well without making a new 
wooden pattern by having a corebox to take out the 
interior space A, using a print for the purpose as shown. 
The thickness of the core will be the same as the width 
B, but the length C and width D of the print are unim- 





isnTtsj 



Fig. 273. — Broken Bracket prepared for 
Moulding from. 



portant so long as there is sufficient bearing to carry the 
core without crushing the edges of the bracket mould. 

Frequently the bolt holes are wanted cored. Pocket or 
drop prints have to be put on at E, E to core these. The 
prints may be secured sometimes by plugging up the old 
holes with wood and nailing the pocket prints to these 
plugs. If this is not sufficient, small holes may be drilled 
in the casting and plugged with wood to receive the nails 
from the prints. Bound prints I\ F will be driven into 
the holes in the bosses, giving \ in. allowance for boring. 
The moulding will be done with the bosses in bottom 
and top — that is, as tho right-haud iigure lies — and the 



MISCELLANEOUS ECONOMIES 



3(57 



parting in the mould will be along the top face of the 
print A. A corebox (Fig. 274) will be made to fill up the 
impression of the main print for coring out the space A , 
and the small facing bosses will be put in the core. The 
thickness B of the box corresponds with the thickness B 
of the print in Fig. 273, the length C with C in that 
figure, and the width D with the width D. The time 
saved is that of making the whole of the pattern proper, 
omitting the print and corebox, which would have to be 
done if a new wood pattern was made. 

With regard to shrinkage, if the height of the casting 
from foot to centre is im- 
portant, then it is usual to 
attach a thickness piece to 
the face G of the foot, to 
allow for shrinkage, ^, ^, 
or J in., as may be required. 
In small patterns sufficient 
allowance may often be given 
by extra rapping. 

Broken castings are gen- 
erally varnished before being moulded. Vertical faces, 
if rough, must be smoothed with a file; the fiat faces 
need not be. If the vertical faces are very rough, some 
beeswax may be worked in and smoothed over, or finely- 
powdered chalk mixed with varnish, and when hardened, 
glass-papered and varnished. These applications fill up 
the hollow parts of the rough surfaces. 

Fig. 275 shows how a broken pipe bend is prepared for 
moulding from. The ends are plugged with round prints, 
and the broken parts are laid together in the mould 
without any fastening, the moulder seeing that they do 
not shift during ramming. 




Fig. 274. — Core Box for 
Bracket. 



;]()8 



PRACTICAL IRON FOUNDING 



Fig. :276 shows how a common rope or sheave pulley is 
prepared for moulding from. A block of wood is fitted 
roughly to the interior of the groove, simply to assist in 
steadying the print A, which is fitted against the edges 
of the pulley rim, its thickness coming flush with the 
outside of the rim on top and bottom. This sweep is 
worked round the rim, being kept level by the small 
battens, and rammed in successive stages, so forming a 
print for segmental cores, by which the interior shape of 

the rim is produced. Be- 
fore any of this is done, 
the arms are rammed up 
in the bottom and top, a 
joint face being formed 
flush with the top edge B 
of the rim. Then after that 
the sweeped print A is 
worked round, and when 
the cores are laid in they 
come flush with the joint 
face, which lies outside 
them. The corebox is of 
the same section as the interior of the rim, plus the 
added space required to fill up the print impression. 

A point that is very essential when taking moulds 
from broken castings is that the parts must be laid 
accurately in their relative positions for ramming. 
Straightedges, winding strips, and the rule must be used 
to test this. It is easy when ramming a fragmentary 
casting in the floor to get the parts out of truth, and so 
make crooked and winding castings. In many cases a 
levelled bed of sand will aft'ord accuracy to the pieces in 
one plane. If the work is not absolutely level, but is so 





Fig. 275. — Broken Pipe pre- 
pared FOR Moulding. 



MISCELLANEOUS ECONOMIES 



369 



in the main, then the level bed of sand is necessary, and 
holes are dug in it to take those parts that project 
beyond the general plane. 

Among the simplest castings that can be moulded 
from are bearings of ordinary kinds. The only difficulty 
is in adding the due allowance for machining, as boring 
and facing. In very small work a slight increase in the 
size can always be made by excessive rapping. Or a care- 
ful moulder can scrape out the mould a little larger with 
his trowel or cleaner, with or without the aid of thick- 
ness strips laid in the portion to be machined. The safer 
way, however, is to line up the portions which have to 




Fig. 276. — Sheave prepaked for Moulding. 



be faced with sheet lead, or with thin leather or wood, 
and this must be done in many jobs. The linings need 
not necessarily be fastened to the castings. If laid against 
them in the mould that is sufficient. 

A common belt pulley, with single arms, can be easily 
moulded from. The allowance for turning is given by 
laying thin strips of wood around the rim, and the 
moulder, guided by the thickness of these, scrapes out 
the mould so much larger than the broken casting. But 
a wide pulley, with double arms, cannot be moulded 
without making a corebox to take out the space between 
the arms, though all the rest will deliver freely. It would, 
however, cost less to make a corebox than to make an 

B B 



370 PRACTICAL IRON FOUNDING 

entire pulley pattern. But many shops keep pulley pat- 
tern rings and sets of arms of all sizes, and then it is 
cheaper to mould from one of these than to make a 
corebox for the broken casting. 

Using broken castings as patterns frequently gives 
more trouble in making sand joints than if wooden pat- 
terns were made. Speaking very generally, the joints in 
pattern and mould coincide, with some slight variations. 
But all broken castings are destitute of any joints, and 
then there must be the alternative in some cases of 
using cores, in others of making sand joints, and lifts 
against faces frequently vertical, with consequent tearing 
up of the sand; or drawbacks may be used. Thus in 
Fig. 273 the sand must be lifted away from the vertical 
faces above the main core print A. In a pattern these 
portions would be left loose. The wood pattern for the pipe 
in Fig. 275 would be jointed along the centre. Moulded 
from the undivided casting, portions of the top sand are 
bound to fracture, so that more work is thrown on the 
moulder in mending up than when moulding is done 
from properly jointed patterns. 

When allowances for shrinkage are excessive, due to 
the large dimensions of a casting, it results in undue 
thickening up of the parts — the plates or flanges — to 
which the thickening pieces are attached. Sometimes 
this does not matter, but often it is very objectionable, 
as in the rim of a light pulley or the flanges of light 
plates. The due proportioning of metal is interfered 
with, and in some cases fracture is liable to occur. If 
such is the case, then the broken work must not be 
moulded from. Sand can be scraped away without much 
difficulty, but it is very troublesome and unsafe to put it 
on in quantity in parts of a mould. It can only be done 



MISCELLANEOUS ECONOMIES 371 

by hatching up the surface, moistening with the swab, 
and if the substance is sufficient, naiUng also. Then, after 
all, there is risk of scabbing or washing away of portions 
of the added sand. So that, unusual cases apart, the work 
of the moulder is restricted to scraping moulds, mending- 
up only being done where the sand has broken down. 

Often broken castings are also worn or corroded badly 
in places. Sometimes the moulder can make these parts 
good by scraping the mould ; but as a rule the pattern- 
maker takes charge of this, making good the worn por- 
tions with wood, nailed or screwed to plugs in drilled 
holes, or cemented on, or simply laid in place next the 
casting in the mould. Small parts also broken off are 
lost, and then the patternmaker has to supply them. 

There is therefore more in this question of utilizing 
broken castings than appears at first sight. A foreman 
must be able in any given case to determine when old 
castings should be utilized, or the alternative of new 
patterns followed. The device is often highly economical ; 
in other cases it is expensive and unsatisfactory. 

Burning on. — This signifies the mending of fractured 
castings, or imperfect castings due to incomplete running, 
by a process of autogenous soldering of metal to metal. 
It is simply this, that sufficient molten metal is poured 
over the surface against which the union has to be 
effected until local fusion has taken place. Then the 
pouring is stopped, and the casting is afterwards as strong 
there as elsewhere. The danger is lest the local increase 
in temperature should cause fracture of the casting to 
occur in the vicinity. 

Before commencing to burn on, the casting is heated 
in the drying stove, brought out, imbedded in the floor, 
and the particular locality where the fusion is to take 



372 PRACTICAL IRON FOUNDING 

place is heated with red-hot weights placed in proximity 
thereto. This is done to diminish risk of fracture. Sand 
or loam cake is built up around the spot where the new 
portion has to be burned on, and is shaped into the par- 
ticular outline required. A gutter or channel is cut lead- 
ing away from this. The molten metal is now poured 
gently and slowly over the fractured surface, and al- 
lowed to run away through the gutter. The heat of the 
metal soon produces fusion of the surface, and when the 
moulder learns by trial with the end of a rod that fusion 
has taken place, he ceases pouring. To burn on only a 
few pounds of metal several hundredweights have to be 
run over the surface into the gutter. This is broken up 
afterwards. 

Weights of Castings. — The only correct way of calculat- 
ing the weight of metal in a casting is to compute the 
number of cubic inches which it will contain, and multiply 
these by a number expressive of the weight of a unit 
volume of the kind of metal used. The latter is the cubic 
inch — only in very heavy work is the cubic foot employed. 
The following table gives the weight of a cubic inch of 
the common metals and alloys. 

AVeight of cub. in. 
Metal or Alloy. in lb. avoir. 

Cast iron 0.263 

Wrought iron 0.281 

Steel 0.283 

Copper 0.3225 

Brass 0.3037 

Zinc 0.26 

Lead 0.4103 

Tin 0.2636 

Mercury 0.4908 



WEIGHTS OF CASTINGS 



373 



The simplest forms for calculation are those of rect- 
angular outlines. After these come circular sections and 



r- 



f^.^ 



B 



1 



;| 






J 
















'^1 


—1 










^ n 


























-^=^ = 


= ^ 


_n n 


:^. . -^ 


T- r,- 


^ __^ 






c- ^<^ ^ 
V 



^ o 



::§) 



DJ 



/? 



Fig. 277.— Tank Plate. 



regular curves, and then the numerous irregular outlines 
which occur in castings. 




W^^y 



Fig. 278. — Flange and Brackets of Plate. 

As an example of the first, take a common tank plate 
(Figs. 277, 278). The details of this are wholly rectangu- 
lar, and it is only necessary to multiply length by breadth 
by thickness of the various details, as follows. 



374 PRACTICAL IRON FOUNDING 

In estimating weights it is well to set down all the 
details in a weight book, in ink, for future reference, if 
required, thus; the quotients in cubic inches being added 
as reckoned subsequently: 

(Jub, in. 

A 1 plate, 4 ft. x 4 ft. x ^- in - 1440 

7:?, J5, 2 flanges, 4 ft. X 2i in. X 4' in. . . = 180 

C, C, 2 flanges, 3 ft. lOJ in. x 2^ in. x J in. = 174 

2?r X 2?- in. 
Z), 28 brackets, — — '<2~~~ X f i". . . = 05. 5 

1859.5 
Deduct 32 bolt-holes, 4^ in. x •; in. x 4 in. = 13.5 cub. in. 

The whole of the items being thus set down at first, 
there is no risk of omitting anything afterwards. The 
details of the computations need not be given, but the 
results only. The use of the reference letters, A, B, and 
6', enables one to see at a glance whether any item has 
been calculated or not. 

Adding these figures we get 1859.5 total cubic inches. 
Deducting the 32 bolt-holes therefrom, we obtain 1859.5 — 
13.5 = 1846 cubic inches as the solid contents of the tank 
plate. 

Angles or fillets are usually cast round the flanges and 
Ijrackets and they will hardly be less than .! or ^ in. on 
the sides. But instead of reckoning these up, simply knock 
out the 13.5 lb. weight of metal taken out by the holes, 
allowing that much for the added weight of angles. So 
that we say that there are 1859.5 cubic inches in the 
tank plate, and the decimal can be omitted. 

To bring 1859 cubic inches into pounds multiply by 
the number representing the weight of a cubic inch of 



WEIGHTS OF CASTINGS 375 

cast iron given in the table, p. 372 = 0.263 = 489.9 lb., 
say 490 lb. 

In connection with the plate the frequent and consider- 
able divergence between the estimated and actual weights 
may be mentioned. A plate of this or of kindred type is 
certain to exceed the calculated weight unless precautions 
are taken to prevent it. The reason is mainly because of 
the broad superficial area over which enormous liquid 
pressure takes place at the time of casting, causing the 
top flask to rise, with a consequent thickening of the 
casting. If the flask is rather light, and the weighting or 
loading down insufficient, the evil will be magnified; and 
if the moulder rams too lightly, or indulges too much in 
scraping, rubbing, and sleeking, the thickening will be 
still further increased. I have seen plates come out fully 
-fV in. thicker in the central parts than the pattern, with 
the addition of something like ^ cwt. to the calculated 
weight. So it by no means follows that when castings 
are found to vary considerably from the calculated 
weights, the calculations themselves are incorrect. It is 
specially in castings of this general type that we have to 
be on our guard. All broad flat areas tend to increase of 
thickness, while in the case of vertical webs, however 
deep, there is little or no difference in the thicknesses of 
pattern and casting observable. 

Actually, some allowance is made in the pattern shop 
in cases where experience shows that a casting will come 
out thicker than the pattern. If a casting is liable to 
gather by yV in-> the pattern is made ^V in. thinner; if 
I in. thicker, then ^ in. less. A 4 ft. tank plate pattern 
should be made fully ^\ in. less in thickness than the 
thickness given on the drawing; and if the plate were 
larger than 4 ft., thinner still. 



376 



PRACTICAL IRON FOUNDING 



The fly-wheel shown in half plan in Fig. 279, and in 
section in Fig. 280, is an example of a circular casting. 
A, the section to the left is shaded regularly, that to the 
right being shaded to illustrate how it is divided into 
separate sections for convenience of calculation. Taking 
the rim ^4, first. Obtain the mean circumference, and then 
reckon the rim as a straight strijj of metal. The outside 





Fig. 280. 
Fly-wheel. 



diameter is 3 ft., the thickness IS- in. The inner diameter 
is, therefore, 2 ft. 9 in., and the mean diameter will be 
2 ft. 10^ in. Set down the first item of measurement of 
the wheel in tabular form as given on p. 377. 

The inner ring, B, has its section concave and convex, 
and by reducing this to a plain rectangle the concave 
portion, will about compensate for the convex edges. This 



WEIGHTS OF CASTINGS 377 

is sufficiently approximate; and time will only permit of 
practical approximations in all work of this character. So 
we reduce the ring, B, to a rectangular section. Its outer 
diameter is 2 ft. 9 in., and it is 1^ in. wide; therefore its 
mean diameter is 2 ft. 7| in., and its section 1-|- x 1|- in. 
We set down B accordingly in the table. The central boss, 

C, in like manner has a mean diameter of 3f in., and a 
section of 6 x 1|^ in. The ring, D, around the boss has 
a mean diameter of 6 in., and a section of 1|- x IJ in. 

There are now six arms, E, of elliptical section. By 
making the necessary deductions at circumference and 
centre, we get six plain straight arms, each 11^ in. long. 
The meaii section of the ellipse at the centre is 2| x If in. 
To obtain the area of an ellipse, the product of the two 
dimensions is multiplied by 0.7854. So we set down the 
arms, E, as shown in the table. Every item now is tabu- 
lated except the radii, c, by which the arms merge into 
the rim and boss, and these can be neglected, or a small 
allowance lumped on for them. Now: 

Cub. in. 

A, 1 ring 2 ft. 10^ in. dia. x U in. x U in. . = 761 

B, 1 ring 2 ft. 7^ in. dia. x IJ- in. x 11 in. . . = 185.2 
(7, 1 ring 3f in. dia. x 6 in. x 1| in = 69.9 

D, 1 ring 6 in. dia. x 1^ in. x 1^ in = 42.1 

^, 6armslllin. longx2f in. xlf in. xO.7854 = 221 



1279.2 



The circumference of A in the table, of 2 ft. 10^ in. 
= 34.5 in. X 3.14159 = 108.3 in. But it is not usual or 
necessary to take the trouble of calculating circumfer- 
ences or areas, because tables of these are given in en- 
gineers' books of reference. Multiplying 108.3 in. by 



378 



PRACTICAL IRON FOUNDING 



4.5 by 1.5 in. we obtain 761 cubic' inches in the rim, 
and set that down opposite A in the table, p. 377. 




B /'.8i' 

Fig. 281. — Section of Bevel Wheel. 



In a similar way we compute the number of cubic 
inches in each item, and record the results thus found 
in the table, as indicated. 




Fig. 282. — Plan of Wheel Arms. 



The total is 1279.2 cubic inches. Multiplying by 
0.263 we get 336 lb. weight of wheel, or 3 cwt. 

The next illustration is a bevel wheel, Figs. 281, 282. 
There is a major pitch diameter. A, and a minor pitch 
diameter, B. In estimating the sectional areas of the rings 



WEIGHTS OF CASTINGS 379 

formed by teeth and rim we take as our basis the mean 
diameters, C, and I), thus: 

Instead of reckoning the sectional contents of a single 
tooth and multiplying by the number of teeth in the 
wheel, we make a ring of the teeth. Take the " face " 
portion — beyond the pitch line (shaded at a, right-hand 
and in plan) — and turn this over between the " flank" 
portions — below the pitch line (a, left-hand in figure and 
in plan). Say the tooth is 1 in. long (mean dimensions 
are taken to average the taper in the rim), and the flank 
portion ^-q in. long, as figured in section. Turning over 
a to a, we have a ring of metal yV ^^' thick, instead of 
i in., which would be one-half the total length of tooth. 
But the " flank clearance " between tooth face and tooth 
flank will be set off against this, so that yV in. thickness 
of ring will be very approximately correct. So, instead 
of taking the mean pitcJi diameter, C, of the wheel for 
the diameter of the ring of teeth, we take the mean dia- 
meter, E, of the ring of metal yV in. in thickness. This 
is 1 ft. lOf in. diameter. We set down, then, the first 
item as a ring, a, 1 ft. lOf in. diameter by fV i^- ^^^ean 
thickness by 4 in. width of face of tooth. 



a 1 ring 1 ft. lOf in. dia. x ^-^ in. x 4 in 

b 1 ring 1 ft. 10 in. dia. X f in. X 4 in. 

c 1 boss 3-i- in. dia. x 5y in. x H in. . 

d 6 arms 6-o in. long x 2| in. x f in. . 

e 6 arms 81 in. long x 3|- in. x f in. . 



Cub. in. 
= 125 
= 207 

= 72 
= 76 
= 119 



599 



The rim, Z>, of the wheel has a mean diameter of 
1 ft. 10 in., and its mean thickness is f in., and width 



880 PRACTICAL IRON FOUNDING 

4 in. ; we set it down accordingly. The remainder of the 
wheel only embodies modes of dividing out, previously 
explained, so we just jot them down as above from the 
drawing without comment — namely, the boss, c, the flat 
arms, d, and the vertical arms, c. 

The total number of cubic inches is 599. Multiplying 
by 0.263, we have 157 lb. weight of metal, or 1 cwt. 
45 lb. in the wheel. 

The next illustration is a bend pipe (Fig. 283). This 
is wholly circular. In thin castings of this type it is not 
usual to take the mean diameter of the ring or rings of 
metal into which we conveniently divide the castings, 
but to subtract the area of the internal diameter or bore 
from the area of the external diameter, as follows: 

In the pipe shown in the figure the lengths are given, 
as is usual, from the centres of the straight lengths, 
A and B, to the faces of the flanges, D and E. We shall 
find it convenient to deduct the bend portion from the 
straight portion, to facilitate calculation. This gives 
two straight portions, A equalling 3 ft. 6 in. — 9 in. in 
length, and B equalling 1 ft. 1 in. — 9 in. in length, and 
we set these down accordingly: 

Cub. in. 
A = l tube 2 ft. 9 in. long x 4 in. and 5 in. dia. . = 234 
B = l tube 4 in. long x 4 in. and 5 in. dia. . . . = 28.4 
C = quarter bend 56.5 in. circ. x 4 in. and 5 in. dia. = 99 
D and E = 2 flanges 9| in. dia. x 1 ft. thick — 

5 in. hole . . / = 100.8 



462.2 



The bend, C, happens to be a quarter of a circle, with 
mean radius, r, of 9 in. So we say 9 in. x 2 = 1 ft. 6 in. 



WEIGHTS OF CASTINGS 381 

mean diameter = 56 J in. circumference, and we want 
one-fourth of that circumference, and we set down C 
accordingly in list. Last, we have two flanges, D and E, 
each 9J in. diameter x 1 in. thick. From these we have 
to deduct holes 5 in. diameter, equal to the outside dia- 
meter of the pipe, because we took the total lengths of 
A and B over the faces of the flanges. We put down the 
flanges in the list and begin our calculations. 

Taking A first, we obtain the area of 5 in.; subtract 
the area of 4 in. from it, and multiply by 2 ft. 9 in.= 
33 in. We do not go through the process each time of 



f 1 3'- 6 




■„..:'ii,„Illllll).ll>ll>ll}l.-t!ll-\-lir!'i:fll{}l!llllll}>ll,l>.ll<J 



i..I 



Fig. 283.— Bend Pipe. 

squaring the diameter and multiplying by 0.7854, but 
go to a table of diameters and areas. The result is, area 
of 5 in. = 19.6 in.; area of 4 in. = 12.5 in.; then 19.6 in. 
— 12.5 in. = 7.1 in. area of cross-section of pipe, which 
X 33 in. = 234 in., which we set down accordingly in the 
list of items. Then ring B, will also equal 7.1 in. area 
x4 in. = 28.4 in. The cross-section of the bend, 0, is 
also 7.1 in. The mean length of the bend is 56.5 in.-r-4 
= 14 in., and 7.1 in. x 14 in. = 99 in. The area of a 
single flange is the area of 9.5 in. — the area of 5 in. 
= 70 in. — 19.6 in. = 50.4 in. There are two flanges = 
100.8 in. 

The total sectional contents of the pipe is 462 in. 
Multiplying by 263 = 121 lb., or 1 cwt. 9 lb. in the pipe. 



382 PRACTICAL IBON FOUNDING 

Another way to run through the weight of plam pijDes, 
and any plain cyHndrical work, is to make use of a table 
of weights of pipes or columns per foot run. In most 
engineers' books of reference these tables are given for 
cast-iron cylinders 1 ft. long, of diameters ranging from 
2 in. or 3 in. to 24 in., and in thicknesses ranging from 
about ^ in. to 1 in. These tables cover the range of all 
ordinary pipe and column dimensions, and therefore save 
some little time in subtracting areas. Again, it is often the 
practice not to reckon out the flanges on a pipe as flanges, 
but to estimate two flanges as equal to 1 ft. in length of 
the pipe, which in standard pipes is not far out. 

When getting out approximate estimates by direct cal- 
culation there is a good deal of mental work done which 
is not put down in figures. Thus in running through an 
intricate piece of work certain allowances or set-offs are 
made. Certain holes will be set off against certain lugs, 
brackets, corners, angles, and so forth, when one appears 
to about counterbalance the other, so that one would not 
be set down at- all in the calculations, but allowances 
would be mentally made for it. 

Measurements of areas and of volumes have to be 
taken with great expedition, because the element of 
time presses. Generally all rules of mensuration which 
involve much calculation are passed by, and figures are 
averaged into rectangles, triangles, and circles, or parts 
of circles. For the areas in the first case two dimensions 
only have to be multiplied together. In the second the 
base and height, and half the product taken. In the 
third, a table would be consulted. Flat and angular 
surfaces are either brought into square feet, or into feet 
square, and of a definite thickness. Curved surfaces, of 
whatever curve, are either brought into flat surfaces of 



WEIGHTS OF CASTINGS 383 

square feet, or feet square, or into annular rings. In 
either of these forms the weights are easily obtainable 
direct from tables. 

Not only are tables designed for use with a given metal 
employed, but tables are also utilized for metals other 
than those for which they are designed. Thus it is very 
easy and convenient to use tables of weights of wrought 
iron for cast iron and brass. Tables are given for the 
weight of a superficial foot of various thicknesses, and 
of the w^eight of a foot run of bar iron of various thick- 
nesses and widths, and these can be utilized for any 
other metal by the employment of a suitable multiplier, 
often saving the trouble of some considerable calculation 
when a table of similar sections is not available for the 
metal or alloy required. Thus the multiplier 0.9538 
converts the weight of bar iron into that of cast iron, 
0.929 steel into cast iron, 1.15 bar iron into gun metal 
or copper. Not that any single calculation in itself 
amounts to much ; but when hundreds of separate cal- 
culations are in question, a trifle of time saved on each 
makes a lot of difference in the sum total. These tables 
are given in the Appendix. 

Even in calculations for bringing cubic inches into 
pounds, many do not use the multiplier 0.263 given for 
cast iron. It is more accurate than any other. But for 
very rough estimating some simply divide cubic inches 
by 4. This, however, would make a good deal of differ- 
ence in a big casting. But a very fair approximation is 
obtained by dividing inches by 4, and the quotient by 20, 
and adding the two. 



APPENDIX 

TABLE I 

Sand Mixtures 

These mixtures, as stated in Chapter II, p. 12, are given 
as typical and illustrative only of the manner in which 
moulding materials are prepared to suit the ever-varying 
requirements of the foundry. Only from this point of 
view are they to be regarded as of value. 

Two mixtures of strong sand from the Manchester dis- 
trict are : — 

(1) 2 barrows of red sand. 
2 ,, road ,, 

2 riddles of horse-manure. 
5 buckets of coal-dust. 

(2) 2 barrows of red sand. 

4 ,, ground road sand. 

5 sieves of coal-dust. 

1 ,, black sand. 

1 ,, loam. 

Jobbing or common sand: — 

4 barrows of red sand. 

2 ,, ground road sand. 
2 ,, black sand. 

6 sieves of coal-dust. 

c c 



386 PRACTICAL IR0:N FOUNDING 

For small work: — 

3 riddles of red sand. 

3 ,, road ,, 

3 ,, fine yellow sand. 

3 buckets of fine coal-dust. 

For fine wheels: — 

3 riddles of red sand. 

3 ,, fine yellow sand. 

2 buckets of fine coal-dust. 

In the West of England. Strong sand: — 
2 barrows of Seend sand. 

1 ,, Devizes sand. 

2 ,, loam. 

5 buckets of coal-dust. 

2 sieves of horse-manure. 

Sand for light work: — 

5 barrows of black sand. 
5 ,, Seend ,, 

3 buckets of coal-dust. 

Loam: — 

1 barrow of black sand. 
1-i „ Seend „ 



1 



)> 



Devizes sand. 



18 shovels of manure. 

The above mixture with half the amount of dung 
makes a good core sand. 

The core sand used at Banbury is composed of equal 
parts of burnt sand and a porous red sand obtained in 
the vicinity of Birmingham. The dry sand is composed 
of the core sand ground in a mill and thickened with 
clay-wash. The red sand is largely used in Birmingham 



APPENDIX 387 

and Manchester, and, like the Worcester sand, which it 
resembles, is very free and open, being largely self- 
venting. 

In the Bradford district (Yorkshire) a red sand from 
the Doncaster district is employed for general jobbing 
work; it is fairly open. 

'' Winmore," a very open gritty sand, is used for 
strong green sand moulds. 

A yellow sand from Kippax is used for cores and for 
dry sand work. 

For loam: Doncaster or Kippax sand is ground with 
clay-wash, and horse-dung or cow-hair added. 

Mansfield sand (Nottinghamshire) is used for fine 
work; it is a close sand. This is also used in the Eastern 
Counties. A little old sand is mixed with the above, 
according to the class of work. 

The following are from foundries in Bradford : — 

(1) Ordinary green sand is composed either of Ponte- 
fract, Doncaster, or Snaith sand, mixed with 50 per cent, 
of old sand, and 1 part of coal-dust to 8 or 10 of sand, 
according to weight of casting. 

(2) Fine green sand for small moulds and teeth of 
wheels is composed of Mansfield sand, with from 25 to 
50 per cent, of old sand, and 1 part of coal-dust to 15 of 
sand. 

(3) For cores: Pontefract, Doncaster, and Snaith sands 
are used, provided they are free from clay. 

(4) For large cores: dried loam pounded, and horse- 
dung dried and sieved, are mixed with the above sands 
in various proportions. 

(5) Dry sand: for facing — dried loam pounded, and 
brought to consistence of green sand; for box filling — 
old and new sand mixed, and weak clay-wash added. 



388 PRACTICAL JIION FOUNlJINd 

From luiothcr lirm 1 have: — 

(1) For common groen sand: yellow Band from Kippax, 
and red sand from Snaith and Doncastor, each mixed 
with old sand in different proportions, according to the 
(juality of the work. 

(2) For fine wheels: Mansfield sand. 

(B) Strong sand is prepared from Jjiittershaw sand 
mixed with old sand, and coal-dust in varying pro[)or- 
tions. 

(4) Cores: red sand, or yellow sand, mixed with a little 
clay and old sand. 

From a Leeds firm: — 

(1) Common green sand: two-thirds of old sand to 
one-third of new yellow sand; coal-dust to suit work. 

(2) Strong sand : one-half old sand, one-quarter yellow, 
and a quarter red; coal-dust in varying proportions. 

(8) Core sand: two-thirds yellow sand, and one-third 
manure. 

In the London district Erith sand is largely used; in 
Scotland, Belfast and Falkirk sands; each district and 
each sho}) having its own special mixtuies; hut the fore- 
going will sullice to illustrate the method of mixing. 






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394 



PRACTICAL IRON FOUNDING 



TABLE VI. 



SIZES, WEIGHTS, PROOF STRAINS, AND WORKING 
LOADS OF SHORT LINK CRANE CHAIN. 



Size of Chain. 


Approximate 
Weight per 
Foot in lbs. 


Proof Strain 
in Cwts. 


Working Load 
in Cwts. 


3 


1*33 


3675 


20*0 


1-91 


45 -o 


24*0 


I 

J. 


2-33 


65-5 


27*0 


■^ 


325 


75-0 


44-0 


5 

! 

4- 


3-66 


I02'0 


53-0 


5'33 


147-0 


8o-o 


7 

I 


671 


200*0 


IIO'O 


9'33 


268-0 


140-0 


u 


11-9 


334'o 


iSo'o 


u 


14-5 


408-0 


! 220'0 



TABLE VII. 

SIZES, WEIGHTS, WORKING LOADS, AND BREAKING 
STRENGTHS OF HEMP ROPES. 



Circumference 


Weight per Fathom 


Safe Working 


Breaking 


in inches. 


in lbs. 


Loads in Cwts. 


Strain in Cwts. 


2^ 


2-0 


6 


40 


% 


4*o 

50 


12 
18 


80 
120 


51 


7-0 


24 


160 


6* 


90 


30 


200 


64 


io*o 


36 


240 


7 


I2*0 


42 


280 


7k 


i4'o 


48 


320 


8* 


i6-o 


54 


360 


9k 
10 


22-0 


78 


520 


25-0 


84 


560 



APPENDIX 



395 



TABLE VII — continued. 

SIZES, WEIGHTS, WORKING LOADS, AND BREAKING 

STRENGTHS OF ROUND STEEL WIRE ROPES. 



Circumference 


Weight per 


Safe Working 


Breaking 


in inches. 


Fathom in lbs. 


Loads in cwts. 


Strain in cwts. 


I 


I'O 


9 


60 


H 


1-50 


15 


100 


n 


TO 


21 


140 


2*50 


27 


180 


2 


3'5o 


33 


220 


2i 


40 


39 


260 


H 


4-50 


45 


300 


^ 


S'o 


51 


340 


H 


5-50 


60 


4CO 


2| 


6-50 


72 


480 


3i 


8-50 


84 


560 


1^ 


5-0 


90 


6co 


10-50 


100 


720 


^l 


I2'0 


115 


840 


4 


14*0 


126 


960 



TABLE VIII. 
AVERAGE COMPOSITION OF PIG IRON. 



Graphitic carbon : 3' 10 

Combined carbon : 0*04 

Silicon ' 2'i6 

Sulphur o"ii 

Phosphorus ; o'63 

Manganese 0*50 

Iron 94'56 




White. 



2*42 

0-36 
0*87 

roS 



95-27 



39G PRACTICAL IBON FOUNDING 



TABLE IX 

MENSURATION" 

1. — Areas 

1. Rectangle or Parallelogram. Multiply the length by 
the breadth. 

2. Triangle. Multiply the base by the perpendicular 
height, and take half the product. 

Or: From half the sum of the three sides subtract 
each side separately, multiply the half sum and the three 
remainders together; the square root of the product will 
be the area. 

3. Trapezoid. Multiply half the sum of the parallel 
sides into the perpendicular distance between them. 

4. Quadrilateral. Divide the quadrilateral into two 
triangles; the sum of the areas of the triangles is the 
area. 

5. Irregular Polygon. Divide the Polygon into triangles, 
and trapezoids by drawing diagonals; find the areas of 
these as above shown for the area. 

6. Regular Polygon. Multiply the length of a side by the 
perpendicular height to the centre and by the number of 
sides, and half the product will be the area. 

7. Circle. Multiply the square of the radius by 
3-14159. 

Or : Multiply the square of the diameter by 7854. 

8. Circular Ring. Find the area of each circle, and 
subtract the area of the inner circle from the area of the 
outer circle. 



APPENDIX 397 

Or: Multiply the sum of the radii by their difference, 
and the product by 314159. 

9. Sectoi' of a Circle. As 360 is to the number of de- 
grees in the angle of the sector, so is the area of the circle 
to the area of the sector. 

Or : Multiply half the length of the arc of the sector by 
the radius. 

10. Segment of a Circle. Find the area of the sector 
which has the same arc, and subtract the area of the 
triangle formed by the radial sides of the sector and the 
chord of the arc; the difference, or the sum of these 
areas, will be the area of the segment, according as it is 
less, or greater than a semicircle. 

11. Cycloid. Multiply the area of the generating circle 
by three. 

12. Parabola. Multiply the base by the height; two- 
thirds of the product is the area. 

13. Ellipse. Multiply the product of the two axes by 
•7854. 

Note. — The area of an ellipse is equal to the area of a 
circle, of which the diameter is a mean proportional be- 
tween the two axes. 



II. — Volumes 

14. Parallelopiped, Prism, ox Cylinder. Multiply together 
the length, the breadth, and the height, and the product 
will be the volume. 

Or: Multiply the area of the base by the height, and 
the product will be the volume. 

15. Pyramid or Cone. Multiply the area of the base by 
the height, and one-third of the product will be the 
volume. 



398 PRACTICAL IRON FOUNDING 

16. Wedge. To twice the length of the base add the 
length of the edge; multiply the sum by the breadth of 
the base, and by the height. One-sixth of the result will 
be the volume. 

17. Sphere. Multiply the cube of the diameter by 
•5236. 

18. Spherieal Shell. Subtract the cube of the inner 
diameter from the cube of the outer diameter, and multi- 
ply the result by '5236. 

19. Zone of Sphere. To three times the sum of the 
squares of the radii of the ends add the square of the 
height; multiply the sum by the height and by '5236. 

20. Segment of Sphere. To three times the square of 
the radius of the base add the square of the height; 
multiply the sum by the height, and the product by 
•5236. 



APPENDIX 



399 



TABLE X. 

WEIGHT OF TWELVE INCHES SQUARE OF 
VARIOUS METALS. 



Thick Wrought 
ness. J Iron. 


Cast 

Iron. 

lbs. 


Steel. 


Gun 
Metal. 


Brass. 


Copper, 
lbs. 


Tin. 


Zinc. 


Lead. 


inch. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


I 


2"50 


2-34 


2-56 


275 


2*69 


2-87 


2'37 


2'2C 


3-68 


A 


5' 


4-69 


5-12 


5*5 


5-38 


5-75 


475 


4-5 


7-37 


7-50 


7'o} 


7-68 


8-25 


8-07 


8-62 


7-12 


675 


11-05 


I 


lo- 


9-38 


10-25 


ir 


1075 


11-5 


9-5 


9* 


14-75 


-i'6 i'2-5 


1172 


i2-8i 


1375 


13*45 


14-37 


11-87 


1 1-25 


18-42 


1 '^' 


i4'o6 


15-36 


16-50 


16*14 


17*24 


14*24 


13-50 


22-IO 


16*41 


17 '93 


19-25 


18-82 


20-12 


16-17 


15*75 


25-80 


4 20- 


1875 


20-5 


22' 


21-5 


23* 


19- 


18- 


29-5 


■r% 22-5 


2rio 


23-06 


2475 


24-20 


25-87 


21-37 


20*25 


33-17 


i i25- 


23*44 


25-62 


27-50 


26-90 


28-74 


23-74 


22-50 


36-84 


H 27-5 


2579 


28-18 


30-25 


29*58 


31-62 


26-12 


2475 


40-54 


i Iso- 


28-12 


30-72 


33'oo 


32-28 


34-48 


28-48 


27- 


44-20 


H i32'5 


30-48 


33*28 


35*75 


34-95 


37'37 


30-87 


29-25 


47-92 


1 l35- 


32-82 


3.-86 


38-50 


37-64 


40-24 


32-34 


31-5 


51-6 


11 37-5 


35-16 


38-43 


41-25 


40-32 


43-12 


35*6i 


3375 


55-36 


I 


40- 


37*5 


41' 


44* 


43* 


46- 


38* i 


36- 


59* 



400 



PRACTICAL IRON FOUNDING 



TABLE XI. 

WEIGHT OF CAST IRON CYLINDERS 
ONE FOOT LONG. 



External 
Diameter. 






Thickness 


in Inche 


3. 






1 

4 


1 


1 
2 


1 


4 


i 


I 


inches. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


3 


6-75 


9-65 


12-3 


14-6 


i6-6 


18-3 


1 9-6 


3k 


7-98 


11-5 


147 


17-6 


20-3 


22-6 


24-5 


4 


9"20 


13-3 


17-2 


20-7 


24-0 


26-9 


295 


4^ 


io'4 


15-2 


1 9 "6 


23-8 


27-7 


31-1 


34-4 


5 


117 


lyo 


22'I 


26'9 


3i'5 


35*4 


39-3 


5k 


I2*9 


1 8 "9 


24-5 


29-9 


35*2 


397 


44-2 


6 


14-1 


207 


27-0 


33-0 


38-9 


44-0 


49-1 


6i 


15*3 


22'5 


29-5 


36-1 


42-6 


48-3 


54-0 


7 


i6-6 


24-4 


3i'9 


39' I 


46-4 


52-6 


58-9 


7k 


17-8 


26"2 


34*4 


42-2 


50-1 


56-9 


63-8 


8 


19*0 


28-1 


36-8 


45"3 


53-8 


6r2 


68-7 


H 


20'3 


29-9 


39'3 


48-3 


57-5 


65-5 


73-6 


9 


21-5 


31-8 


417 


51*4 


61-3 


69-8 


78-5 


9k 


227 


33-6 


44-2 


54-5 


65-0 


74-1 


83-5 


lO 


23-9 


35'4 


46-6 


57'5 


687 


78-4 


88-4 


II 


26-4 


39' I 


51*5 


637 


76-0 


87-0 


98-2 


12 


28-8 


42-8 


56-5 


69-8 


83-4 


95-6 


108-0 


13 


3i"3 


46-5 


61*4 


75"9 


907 


104-2 


I 17-8 


14 


33-8 


50*2 


66-3 


82-1 


98-0 


I 12-8 


127-6 


15 


36*2 


53-8 


7 I '2 


88-2 


105-4 


121-3 


137-4 


i6 


387 


57-5 


76-1 


94*3 


112-7 


129-9 


147-3 


17 


41-1 


6r2 


81 -o 


ioo*5 


I20-0 


138-5 


157-1 


i8 


43 "6 


64-9 


85-9 


io6"6 


127-4 


147-1 


166-9 


19 


46*0 


68-6 


90-8 


II2-8 


1347 


1557 


1767 


20 


48-5 


72-3 


957 


118-9 


142-0 


164-3 


186-5 


21 


50-9 


75-9 


ico'6 


125-0 


149-4 


172-9 


196-4 


22 


53-4 


79-6 


105-5 


131-2 


1567 


181-5 


206-2 


23 


55-8 


83-3 


iio*5 


137-3 


164-0 


190-1 


215-0 


24 


58-3 


87-0 


115-4 


I43'4 


I7I-4 


1987 


225-8 



APPENDIX 



401 



TABLE XI — co7itinued. 









Thickness in Inches. 




T^.vfernal 












Diameter. 


1 
4 


I 


1 
2 


1 


3 

4 




inches. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs 


lbs. 


25 


6o-8 


907 


120-3 


149-6 


178-7 


207-2 


235-6 


26 


63*2 


94-3 


125-2 


^557 


I86-I 


215-8 


245*4 


27 


657 


98-0 


1 30- 1 


161-8 


193*4 


224-4 


255*3 


28 


68-1 


101-7 


i35"o 


i68-o 


200-7 


233-0 


265*1 


29 


70-6 


105-4 


139*9 


174-1 


208-1 


241-6 


274-9 


30 


73'o 


109-1 


144-8 


i8o-2 


215-4 


250-2 


284-7 


31 


75'5 


II2-8 


1497 


IS6-4 


222-7 


258-8 


294-5 


32 


77-9 


1 16-4 


154-6 


192-5 


230-1 


267-4 


304-3 


33 


80-4 


I20*I 


159*5 


198-7 


237*5 


276-0 


314-2 


34 


82-8 


123-8 


164-5 


204-8 


244-8 


284-6 


324-0 


35 


85-3 


127-5 


169-4 


210-9 


252-2 


293-1 


333*8 


36 


87-8 


131-2 


174*3 


2I7-I 


259*5 


301-7 


343*6 


38 


927 


138-5 


1 84- 1 


229-3 


274-3 


318-9 


363-2 


40 


97 '6 


1 45 "9 


193*9 


241-6 


289-0 


336-1 


382-9 


42 


I02'5 


153*3 


203-7 


253*9 


303*7 


353*3 


402-5 


45 


109-8 


1 64*3 


218-5 


272-3 


325*8 


379*1 


432-0 


48 


117*2 


i75'4 


233-2 


290-7 


347*9 


404-8 


461*4 


51 


1 24*6 


186-4 


247-9 


309-1 


370-0 


430-6 


490-9 


54 


131-9 


197-5 


262-6 


327*5 


392-1 


456-4 


520-3 


SI 


i39"3 


208-5 


277-4 


345*9 


414-2 


482-1 


549*8 


60 


146-6 


219-6 


292-[ 


364*3 


4.36-3 


507-9 


579*3 



D D 



402 



PRACTICAL IRON FOUNDING 



TABLE XII. 
COMPARATIVE WEIGHTS OF DIFFERENT BODIES. 



Cast Iron = i 



Bar Iron 

Steel 

Brass 

Copper 

Gun metal 

Lead 



= 1*0484 
= I •0766 

= i'i53 
= 1-2137 
= 1*208 
= 1-5645 



Bar Iron = I 



Cast iron 

Steel 

Brass 

Copper 

Gun metal 

Lead 



= -9538 
= 1-0269 
= ri 

= 1-15163 
= 1*15094 

= i"5 



Steel = I 



Cast iron 
Bar iron 
Brass 
Copper 
Gun metal 
Lead 



= -929 

= '97378 
= 1*07 
= 1*1236 
= 1*12132 
= I '4532 



Brass = 


= 1 


Copper: 


= 1 


Gun Metal = I 


Cast iron 


= -867 


Cast iron 


= -83 


Cast iron 


= -82888 


Bar iron 


= -909 


Bar iron 


= -8666 


Bar iron 


= -86874 


Steel 


= '9336 


Steel 


= *89 


Steel 


= -891735 


Copper 


= 105 


Brass 


= '95 


Brass 


= -95583 


Gun metal 


= 1-046^ 


Gun metal 


= *9994 


Copper 


= I -00045 


Lead 


= 1*357"' [Lead 


= 1-293 


Lead 


= I -29246 



Lead=i 


Yellow Pine = I 


Cast iron = '64 
Bar iron = -67 
Steel =*688 
Brass = '737 
Copper = '774 
Gun metal = '7736 


Cast iron =16*0 
Steel =17*0 
Brass =i8-8 
Gun metal =19-0 
Copper =I9'3 
Lead = 24*0 



APPENDIX 



403 



TABLE XIII. 
WEIGHT OF CAST IRON BALLS. 



Diameter 
in inches 


Weight 
in lbs. 


2 


rio 




1-57 


2i 


215 

2-86 


3 


372 


34 

H 

3i 

4 


471 
5 -So 
7-26 
8-8i 


4i 


IO-57 


41 

4| 


i2'55 
1476 


5 


I7*I2 


5i 


19-93 1 


5i 
Si 


22-91 1 
26-18 ' 



Diameter 
in inches. 



Weight 
in lbs. 



6 
^^ 

H 

7 

7i 

7k 
7^- 
8^ 

H 

H 
9 

9i 
9k 
9l 



29-72 
33-62 
37-80 

43-35 
47-21 

52-47 

58-06 

64-09 

70-49 

77*32 

84-56 

92-24 

100-39 

108-98 

118-06 

127-63 



Diameter 
in inches. 



10 

lol 
io| 
1 1 

12 
I2i 

13 

I3i 
13^ 

1 31 



Weight 
in lbs. 



I377I 
148-28 
159-40 
171-05 
183-29 
196-10 
209-43 
223-40 
237-94 

253"i3 
268-97 

285-37 
302-41 

320-80 

338-81 

357-93 



404 



PRACTICAL IRON FOUNDING 



TABLE XIV. 

DECIMAL EQUIVALENTS TO FRACTIONAL PARTS 
OF LINEAL MEASURES. 

One inch the integer or whole number. 



•96875 




1 & T^ 


•6.5 




5 


•28125 




J. & _^- 

4 "'■ 3Z 


•9375 




•59375 






•25 




I 
4- 


•90625 




1 & i. 


•5625 




a *^ 16 


•21875 




i & A 


•875 



4-' 


7 


•53125 




■4-> 




•1875 





if'^ 


•84375 


1^ 


3 /?r 3 


*5 


■^ 


I 
■z 


•15625 


n 




•8125 


3 
0^ 


•46S75 


0^ 


i & 3\ 


\'12S 


0^ 


r 

8 


•78125 


(L) 


•4375 




1&T-, 


i ^0937 5 




1 
3z 


75 


a 


•40625 


c5 


1 '^ ^^" 
8 


1 ^062 5 




I 


•71875 




i & A 


•375 




1 '03125 




I 

Hi 


•6875 




5^1 


•34375 




i & A 


i 






•65625 




•3125 




i&T's 


1 

1 







TABLE XV. 



DECIMAL APPROXIMATIONS FOR FACILITATING 
CALCULATIONS IN MENSURATION. 



Square inches multiplied by 


•007 


= 


Square feet. 


Cubic inches 




J) 


•00058 


= 


Cubic feel 




J) J) 




jj 


•263 


= 


Lbs. Avs. 


of Cast iron. 


}) )) 




>j 


•281 


= 






„ Wrought iron. 


91 n 




>) 


•283 


= 






„ Steel. 


« » 


»> 


» 


•3225 


= 






„ Copper. 


if if 




» 


•3037 


= 






„ Brass. 


)) )) 




» 


•26 


= 






„ Zinc. 


)> ') 


» 


» 


•4103 


— 






„ Lead. 


»> >» 




j> 


•2636 


= 






„ Tin. 


jj j> 




>j 


•4908 


= 






„ Mercury. 


Avoirdupois lbs. 




>> 


•009 


= 


Cwts. 






»> " 




51 


•00045 


= 


Tons. 







INDEX 



Aluminium, 35. 
Analysis of sands, 15-17. 
Angles in castings, 132. 
Anvil block, 163. 
Ai5pendix : 
Tables I. Sand mixtures, 385. 

,, II, III. Particulars, "Ra- 
pid" cupolas, 389, 
390. 

,, IV. Particulars, Root's 
bloAvers, 392. 

,, V. Sturtevant fans, 393. 

,, VI. Crane chains, 394. 

,, VII. Ropes, various, 394, 
395. 

,,VIII. Composition of pig 
iron, 395. 

,, IX. Mensuration, 396- 
398. 

,, X. Weights of various 
metals, 399. 

,, XI. Weights of cast iron 
cylinders, 400,401. 

,, XII. Comparative weights, 
402. 

,,XIII. Weights, cast iron 
balls, 403. 

,, XIV. Decimal equivalents, 
404. 

,, XV. Decimal approxima- 
tions, 404. 

Back plates, 101. 
Bar tester, 38. 
Bars, 94, 95. 



Bead tools, 112. 

Bedding-in, 138. 

Bend pipe, 259. 

Bessemer converters, 91. 

Black sand, 7. 

Black wash, 13. 

Blackening, 13. 

Blacking, 13. 

Blacking, wet, 13. 

Blast, 60. 

Blowers, 62-64. 

Blow holes, 124. 

Bogie tracks, 75. 

Bottom boards, 263. 

Box filling, 7. 

Bricking up, 238. 

Bricks, 238. 

Bricks, loam, 120. 

Broken castings, moulding from, 

364-371. 
Buckley and Taylor's wheel 

moulding machine, 329-334. 
Burning on, 371. 
Burnt iron, 31. 
Burnt sand, 12. 

Calipers, 238. 
Casting bosses, 177. 
Casting ladles, 65-70. 
Casting on end, 188. 
Casting pits, 76. 
Castings, curving of, 114. 
Castings, shrinkage of, 113. 
Castings, weight of, 372-383. 
Chains, 394. 



405 



406 



INDEX 



Chaplets, 225. 

Charcoal, 13. 

Charging of cupolas, 50, 51. 

Checks, 246. 

Chilling, 44, 45. 

Cinder bed, 144. 

Cinders, 144, 239. 

Clay plugs, 162. 

Clean castings, 13. 

Cleaner, 110. 

Coal dust, 9. 

Coal, grinding of, 26. 

Coal mill, 26. 

Coke, 53. 

Coke bed, 164, 228. 

Cold shuts, 128. 

Collapsible core bars, 84. 

Compressed air, 87. 

Converters, 91. 

Copes, 93, 94. 

Core bars, 218. 

Core bars, collapsible, 220. 

Core carriage, 93. 

Core grids, 217. 

Core irons, 218. 

Core making, 192-197, 232. 

Core making machines, 319. 

Core ovens, 74. 

Core plates, 219. 

Core prints, 223, 228. 

Core ropes, 220. 

Core sand, 11. 

Core stoves, 74, 228. 

Core strings, 221. 

Core vents, 221, 227. 

Cores, 215-233. 

Cores, drying of, 11, 74. 

Cores, green sand, 11. 

Cores, grids for, 217- 

Crane chains, 394. 

Cranes, 81. 

Crystallization, 116. 

Cupola blast, 60. 

Cupola, charging of, 53. 



Cupola, chemical actions, 54. 
Cupola, drop bottom, 59. 
Cupola furnaces, 46-60, 73. 
Cupola, " Rapid," 55, 56. 
Cupola tuyeres, 49, 57, 58. 
Curving of castings, 114. 
Cylinder moulding, 187, 197-209. 

Decimal approximations, 404. 

Decimal equivalents, 404. 

Delivery of patterns, 148, 272. 

Drags, 93, 95. 

Drawing of castings, 128-132. 

Drawing of patterns, 363-364. 

Drop bottom, 59. 

Dry sand, 10. 

Dry sand, moulding in, 185. 

Drying, 10. 

Drying stoves, 74. 

Electric power, 86. 

Facing sand, 8. 
Fans, 61, 62, 64. 
Feeder head, 160. 
Feeder rods, 160. 
Feeding, 159. 
Fillets, 133. 
Finning, 185. 
Flasks, 93-108. 
Flasks, forms of, 101. 
Flow off gates, 161. 
Forms of flasks, 101. 
Forms of prints, 86. 
Foundries, 71-92. 
Foundry cranes, 81. 
Foundry pit, 76, 77. 
Fracture of castings, 115. 

Gear moulding-bevels, 344. 
Gear moulding machine, 328-334. 
Gear moulding-spurs, 335. 
Geared ladles, 67. 
Goodwin and How's patent ladle, 
70. 



INDEX 



407 



Green sand, 6. 

Green sand cores, 11. 

Green sand moulding, 163-184. 

Gray iron, 30. 

Grids, 217, 218, 342. 

Guide irons, 258. 

Hard ramming, 126, 127, 186. 

Hay bands, 218. 

Head metal, 209-214. 

Heating, 90. 

Hemp roj)es, 197. 

Hollows, 133. 

Honeycombing, 122. 

Horse manure, 10. 

Hydraulic moulding machines, 

310-314, 317. 
Hj^draulic power, 88. 

Ingates, 154, 156, 158. 

Iron, 28-46. 

Iron and aluminium, 35, 36. 

Iron, burnt, 31. 

Iron, economical melting of, 59. 

Iron, foreign constituents of, 35. 

Iron, gray, 30. 

Iron, mottled, 31. 

Iron, pig, 29. 

Iron, remelting, 34, 35. 

Iron, testing of, 36-44. 

Iron, white, 30. 

Jar-ramming moulding machines, 

323-326. 
Joint boards, 263. 
Joints, 98, 140, 163, 185, 190. 
Joints, lapping, 133. 

Ladles, 65-70. 

Ladles, geared, 67. 

Ladles, Goodwin and How's 

patent, 70. 
Lapping joints, 133. 
Liftering, 147. 
Lifters, 146. 



Loading, 100. 

Loam, 11. 

Loam boards, 236, 248. 

Loam bricks, 120, 242. 

Loam cakes, 152, 159. 

Loam mill, 19. 

Loam moulding, 234-251. 

Loam patterns, 252-262. 

Loam plates, 236, 240, 244, 250, 

256. 
Loam work, 234-251. 

Machine moulded gears, 329-346. 
Machine moulding, 262-346. 
Machines, 81, 89. 
Machines for sand preparation, 

19-27. 
Manganese, 35. 
Melting ratio, 58, 59. 
Mending up, 148. 
Mending up pieces, 149. 
Mensuration, 396. 
Middle parts, 93, 96. 
Mixing of sand, 12, 18-27. 
Mottled iron, 31. 
Mould for cylinder cover, 156. 
Mould for anvil block, 163. 
Mould press, 279. 
Moulding a tuyere, 229. 
Moulding boxes, 93-108. 
Moulding by machine, 262-346. 
Moulding a cross, 177. 
Moulding cylinders, 187, 197-209. 
Moulding in dry sand, 185. 
Moulding in green sand, 163-184. 
Moulding in loam, 234-251. 
Moulding in open sand, 137. 
Moulding machines, 278, 283, 284, 

286, 294, 295, 297, 301, 302, 306, 

312, 313, 315, 316. 
Moulding, plate, 264. 
Moulding of fly-wheel, 166. 
Moulding of sheave wheel, 141, 

142. 



408 



INDEX 



Moulding? of trolly Avheel, 140, 

264. 
Moulding, principles of, 1. 
Moulding sand, 1, % 4-27. 
Moulding a soap pan, 247. 
Moulds, permanent, 45. 
Multiple moulding, 315. 

Nailing, 147. 

Offices, 78. 
Old sand, 7. 
Open sand, 137. 

Parting sand, 12. 
Patterns, delivery of, 148. 
Pattern of fly-wheel segment, 

168, 170. 
Patterns, 2, 3, 348. 
Patterns in loam, 252. 
Permanent moulds, 45. 
Phosphorus, 35. 
Pig iron, 29. 
Pits, 76. 

Plate moulding, 264. 
Plated patterns, 265-269. 
Plugs, 162, 166. 
Plumbago, 13. 
Pocket prints, 224. 
Portable moulding machine, 295. 
Pouring, 150. 
Pouring basins, 152. 
Pouring moulds, 150. 
Power, 83. 

Pressure, 100, 134, 166. 
Prints, forms of, 223. 
Prints, pocket, 224. 
Prods, 242. 
Pumping, 159. 

Hammers, 108, 109. 
Ramming, 269. 
Rapping, 148, 272, 273. 
Reverse mtmld, 168, 343, 344. 
Riddles, 22, 23. 



Risers, 154, 161. 

Rockover moulding macnines, 

294. 
Rodding, 146. 

Root's rotary blower, 63, 392. 
Ropes, hem}), 394. 
Ropes, wire, 394, 395. 
Runner spray, 157. 
Runner stick, 157. 
Runners, 152, 158. 
Running, 152, 

Sand, 1, 2, 4-27. 

Sand, black, 7. 

Sand, burnt, 12. 

Sand, chemistry of, 14. 

Sand, core, 11. 

Sand, dry, 10. 

Sand, facing, 8. 

Sand, green, 6. 

Sand, grinding, 19. 

Sand, machines for, 19. 

Sand, mixing of, 12, 18-27. 

Sand, parting, 12. 

Sand, preparation of, 18-27. 

Sand sifters, 20-23. 

Scabbing, 126, 

Scrap, 29, 32, 34, 

Shops, 71-92. 

Shrinkage, 41-43. 

Shrinkage of castings, 113, 

Sieves, 22, 23. 

Silicon, 35, 42, 43. 

Skimmer, 70. 

Skimming chamber, 154. 

Skin drying, 10. 

Slagging, 51. 

Sleekers, 112. 

Sleeking, 127. 

Snap flasks, 103-108. 

Soap pan, 247. 

Socket bend, 259. 

Soft ramming, 127. 

Specialization, 320, 327. 



INDEX 



409 



Spray of runners, 157. 

Sprigging, 147. 

Sprigs, 147. 

Staking, 98. 

Stays, 94-90. 

Steam power, 85. 

Stewart's patent " Rapid " cupola, 

55, 390. 
Stopping off, 361-363. 
Stopping over, 224. 
Stops, 225. 
Stoves, 74, 228. 
Strap, 236. 

Strickles, 258, 350, 351, 353. 
Strickling, 258-261, 350, 353. 
Striking bar, 235. 
Striking boards, 236, 335, 338- 

340, 343-345, 359. 
Stripping plates, 273, 292, 306. 
Strong sand, 8. 
Sulphur, 35. 
Swab, 148. 
Swabbing, 148. 
Sweeping up, 166. 
Swivels, 101. 

Taper, 3. 

Tapping of metal, 50, 51. 

Tar, 252. 

Test bars, 37, 43. 

Testing machine, 38. 

Thicknessing, 258, 260, 261. 

Three parted mould, 142. 

Tools, 108-112 

Top parts, 93. 



Tacks, 75. 

Trowels, 110. 

Turn over boards, 263. 

Turning over, 139, 143, 271. 

Tuyere moulding, 229. 

Universal moulding machine, 
297. 

Vent pipes, 144, 164, 179, 228. 
Vent wires, 109. 
Ventilation, 90. 
Venting, 144. 
Venting in loam, 103. 
Vents, 144. 

Vents, choking of, 144. 
Vents, securing of, 227. 
Vibrator frame moulding ma- 
chine, 302. 

Weighting, 100. 
Weights, comparative, 402. 
Weights of castings, 372-383. 
Weights of cast iron balls, 403. 
Weights of cast iron cylinders, 

400. 
Weights of metals, 399. 
Wet blacking, 13. 
Wheel moulding machine, 329- 

334. 
Wheel teeth, 335, 337. 
Wheels, moulding of, 329, 361- 

364. 
White iron, 30. 
Wire ropes, 395. 



CHISWICK PRESS: PRINTED BY CHARLES WHITTINGHAM AND CO. 

TOOKS COURT, CHANCERY LANE, LONDON. 

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JUIN 4 191J^ 



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